Examples with solutions for Addition of Fractions: Finding a Common Denominator by Multiplying the Denominators

Exercise #1

Solve the following exercise:

14+19= \frac{1}{4}+\frac{1}{9}=

Video Solution

Step-by-Step Solution

Let's try to find the lowest common denominator between 4 and 9

To find the lowest common denominator, we need to find a number that is divisible by both 4 and 9

In this case, the common denominator is 36

Now we'll multiply each fraction by the appropriate number to reach the denominator 36

We'll multiply the first fraction by 9

We'll multiply the second fraction by 4

1×94×9+1×49×4=936+436 \frac{1\times9}{4\times9}+\frac{1\times4}{9\times4}=\frac{9}{36}+\frac{4}{36}

Now we'll combine and get:

9+436=1336 \frac{9+4}{36}=\frac{13}{36}

Answer

1336 \frac{13}{36}

Exercise #2

14+36= \frac{1}{4}+\frac{3}{6}=

Video Solution

Step-by-Step Solution

To solve the problem of adding 14 \frac{1}{4} and 36 \frac{3}{6} , we perform the following steps:

  • Step 1: Find the least common multiple (LCM) of the denominators 44 and 66. The LCM of 44 and 66 is 1212.
  • Step 2: Convert 14 \frac{1}{4} to an equivalent fraction with a denominator of 1212.
    Multiply both the numerator and denominator of 14 \frac{1}{4} by 33 to get 312 \frac{3}{12} .
  • Step 3: Convert 36 \frac{3}{6} to an equivalent fraction with a denominator of 1212.
    Multiply both the numerator and denominator of 36 \frac{3}{6} by 22 to get 612 \frac{6}{12} .
  • Step 4: Add the equivalent fractions 312+612 \frac{3}{12} + \frac{6}{12} .
  • Step 5: Combine the numerators while keeping the common denominator: 3+612=912 \frac{3+6}{12} = \frac{9}{12} .
  • Step 6: Simplify 912 \frac{9}{12} by dividing the numerator and the denominator by their greatest common divisor, which is 33, resulting in 34 \frac{3}{4} .

Therefore, the sum of 14 \frac{1}{4} and 36 \frac{3}{6} is 34 \frac{3}{4} .

Answer

34 \frac{3}{4}

Exercise #3

Solve the following exercise:

15+13=? \frac{1}{5}+\frac{1}{3}=\text{?}

Video Solution

Step-by-Step Solution

To solve the problem of adding the fractions 15 \frac{1}{5} and 13 \frac{1}{3} , we follow these steps:

  • Step 1: Find a common denominator for the fractions. Since the denominators are 55 and 33, the least common multiple is 1515.
  • Step 2: Convert each fraction to this common denominator:
    - For 15 \frac{1}{5} , multiply both numerator and denominator by 33 (the denominator of the other fraction), resulting in 315 \frac{3}{15} .
    - For 13 \frac{1}{3} , multiply both numerator and denominator by 55 (the denominator of the other fraction), resulting in 515 \frac{5}{15} .
  • Step 3: Add the fractions now that they have a common denominator:
    315+515=3+515=815\frac{3}{15} + \frac{5}{15} = \frac{3+5}{15} = \frac{8}{15}.

Therefore, when you add 15 \frac{1}{5} and 13 \frac{1}{3} , the solution is 815 \frac{8}{15} .

Answer

815 \frac{8}{15}

Exercise #4

25+14= \frac{2}{5}+\frac{1}{4}=

Video Solution

Step-by-Step Solution

To solve the problem, let's follow a structured approach:

  • Step 1: Determine the least common multiple (LCM) of the denominators (5 and 4). The LCM of 5 and 4 is 20.
  • Step 2: Adjust each fraction to have the common denominator of 20.
    For 25 \frac{2}{5} , multiply both numerator and denominator by 4 to get 820 \frac{8}{20} .
    For 14 \frac{1}{4} , multiply both numerator and denominator by 5 to get 520 \frac{5}{20} .
  • Step 3: Now, add the two fractions:
    820+520=8+520=1320 \frac{8}{20} + \frac{5}{20} = \frac{8 + 5}{20} = \frac{13}{20} .
  • Step 4: Verify if the fraction needs simplification. In this case, 1320 \frac{13}{20} is already in its simplest form.

The resulting fraction after adding 25 \frac{2}{5} and 14 \frac{1}{4} is 1320 \frac{13}{20} .

Answer

1320 \frac{13}{20}

Exercise #5

Solve the following exercise:

38+23= \frac{3}{8}+\frac{2}{3}=

Video Solution

Step-by-Step Solution

Let's try to find the least common multiple (LCM) between 8 and 3

To find the least common multiple, we need to find a number that is divisible by both 8 and 3

In this case, the common multiple is 24

Now we'll multiply each fraction by the appropriate number to reach the denominator 24

We'll multiply the first fraction by 3

We'll multiply the second fraction by 8

3×38×3+2×83×8=924+1624 \frac{3\times3}{8\times3}+\frac{2\times8}{3\times8}=\frac{9}{24}+\frac{16}{24}

Now we'll combine and get:

9+1624=2524 \frac{9+16}{24}=\frac{25}{24}

Answer

2524 \frac{25}{24}

Exercise #6

35+27= \frac{3}{5}+\frac{2}{7}=

Video Solution

Step-by-Step Solution

To solve the given problem, we will follow these steps:

  • Step 1: Determine a common denominator for the fractions.
  • Step 2: Convert each fraction to have the common denominator.
  • Step 3: Add the numerators and keep the common denominator.
  • Step 4: Simplify the resulting fraction if possible.

Let's proceed with each step:

Step 1: Determine a common denominator.
The denominators of the fractions are 5 and 7. The least common multiple (LCM) of 5 and 7 is 35. Thus, the common denominator is 35.

Step 2: Convert each fraction to have the common denominator of 35.
Convert 35\frac{3}{5} to a fraction with a denominator of 35: 35=3×75×7=2135 \frac{3}{5} = \frac{3 \times 7}{5 \times 7} = \frac{21}{35} .
Convert 27\frac{2}{7} to a fraction with a denominator of 35: 27=2×57×5=1035 \frac{2}{7} = \frac{2 \times 5}{7 \times 5} = \frac{10}{35} .

Step 3: Add the numerators and use the common denominator.
Now add the fractions: 2135+1035=21+1035=3135 \frac{21}{35} + \frac{10}{35} = \frac{21+10}{35} = \frac{31}{35} .

Step 4: Simplify the result.
The fraction 3135\frac{31}{35} is already in its simplest form since 31 and 35 have no common factors other than 1.

Therefore, the solution to the problem is 3135 \frac{31}{35} .

Answer

3135 \frac{31}{35}

Exercise #7

45+13= \frac{4}{5}+\frac{1}{3}=

Video Solution

Step-by-Step Solution

To solve 45+13\frac{4}{5} + \frac{1}{3}, follow these steps:

  • Step 1: Identify a common denominator for the fractions. The current denominators are 55 and 33, hence their common denominator is 1515 (since 5×3=155 \times 3 = 15).
  • Step 2: Convert each fraction to an equivalent fraction with the common denominator 1515:
    • For 45\frac{4}{5}: multiply the numerator and the denominator by 33 (since 5×3=155 \times 3 = 15).
      45=4×35×3=1215\frac{4}{5} = \frac{4 \times 3}{5 \times 3} = \frac{12}{15}.
    • For 13\frac{1}{3}: multiply the numerator and the denominator by 55 (since 3×5=153 \times 5 = 15).
      13=1×53×5=515\frac{1}{3} = \frac{1 \times 5}{3 \times 5} = \frac{5}{15}.
  • Step 3: Add the converted fractions:
    1215+515=12+515=1715\frac{12}{15} + \frac{5}{15} = \frac{12 + 5}{15} = \frac{17}{15}.

Therefore, the solution to the problem is 1715\frac{17}{15}.

Answer

1715 \frac{17}{15}

Exercise #8

49+12= \frac{4}{9}+\frac{1}{2}=

Video Solution

Step-by-Step Solution

To solve the problem of adding 49\frac{4}{9} and 12\frac{1}{2}, we'll proceed step-by-step:

  • Step 1: Determine a common denominator.
  • Step 2: Convert each fraction to an equivalent fraction with this common denominator.
  • Step 3: Add the numerators of these converted fractions.
  • Step 4: Simplify the resulting fraction if necessary.

Now, let's perform these steps in detail:

Step 1: Determine the common denominator.
The denominators are 9 and 2. The least common denominator (LCD) can be found by multiplying these because they have no common factors other than 1:
LCD=9×2=18 \text{LCD} = 9 \times 2 = 18 .

Step 2: Convert each fraction to have the common denominator of 18.

  • Convert 49\frac{4}{9}: 49=4×29×2=818 \frac{4}{9} = \frac{4 \times 2}{9 \times 2} = \frac{8}{18}
  • Convert 12\frac{1}{2}: 12=1×92×9=918 \frac{1}{2} = \frac{1 \times 9}{2 \times 9} = \frac{9}{18}

Step 3: Add the numerators of the converted fractions:
818+918=8+918=1718 \frac{8}{18} + \frac{9}{18} = \frac{8+9}{18} = \frac{17}{18}

Step 4: Simplification (if needed):
The fraction 1718\frac{17}{18} is already in its simplest form.

Therefore, the sum of 49\frac{4}{9} and 12\frac{1}{2} is 1718 \frac{17}{18} .

Answer

1718 \frac{17}{18}

Exercise #9

Solve the following exercise:

12+27=? \frac{1}{2}+\frac{2}{7}=\text{?}

Video Solution

Step-by-Step Solution

To solve the given problem of adding two fractions 12 \frac{1}{2} and 27 \frac{2}{7} , follow these steps:

  • Step 1: Determine the common denominator.

The denominators of the fractions are 22 and 77. Multiply these two numbers to find the common denominator: 2×7=142 \times 7 = 14.

  • Step 2: Adjust each fraction to have the common denominator.

Convert 12 \frac{1}{2} to an equivalent fraction with a denominator of 1414:
12=1×72×7=714 \frac{1}{2} = \frac{1 \times 7}{2 \times 7} = \frac{7}{14}

Convert 27 \frac{2}{7} to an equivalent fraction with a denominator of 1414:
27=2×27×2=414 \frac{2}{7} = \frac{2 \times 2}{7 \times 2} = \frac{4}{14}

  • Step 3: Add the adjusted fractions.

Now that both fractions have a common denominator, add them:
714+414=7+414=1114 \frac{7}{14} + \frac{4}{14} = \frac{7 + 4}{14} = \frac{11}{14}

We have successfully added the fractions and obtained the result.

Therefore, the solution to the problem is 1114 \frac{11}{14} .

Answer

1114 \frac{11}{14}

Exercise #10

Solve the following exercise:

12+29= \frac{1}{2}+\frac{2}{9}=

Video Solution

Step-by-Step Solution

Let's try to find the lowest common denominator between 2 and 9

To find the lowest common denominator, we need to find a number that is divisible by both 2 and 9

In this case, the common denominator is 18

Now we'll multiply each fraction by the appropriate number to reach the denominator 18

We'll multiply the first fraction by 9

We'll multiply the second fraction by 2

1×92×9+2×29×2=918+418 \frac{1\times9}{2\times9}+\frac{2\times2}{9\times2}=\frac{9}{18}+\frac{4}{18}

Now we'll combine and get:

9+418=1318 \frac{9+4}{18}=\frac{13}{18}

Answer

1318 \frac{13}{18}

Exercise #11

Solve the following exercise:

14+26= \frac{1}{4}+\frac{2}{6}=

Video Solution

Step-by-Step Solution

Let's try to find the lowest common denominator between 4 and 6

To find the lowest common denominator, we need to find a number that is divisible by both 4 and 6

In this case, the common denominator is 12

Now we'll multiply each fraction by the appropriate number to reach the denominator 12

We'll multiply the first fraction by 3

We'll multiply the second fraction by 2

1×34×3+2×26×2=312+412 \frac{1\times3}{4\times3}+\frac{2\times2}{6\times2}=\frac{3}{12}+\frac{4}{12}

Now we'll combine and get:

3+412=712 \frac{3+4}{12}=\frac{7}{12}

Answer

712 \frac{7}{12}

Exercise #12

Solve the following exercise:

17+13= \frac{1}{7}+\frac{1}{3}=

Video Solution

Step-by-Step Solution

Let's try to find the lowest common denominator between 7 and 3

To find the lowest common denominator, we need to find a number that is divisible by both 7 and 3

In this case, the common denominator is 21

Now we'll multiply each fraction by the appropriate number to reach the denominator 21

We'll multiply the first fraction by 3

We'll multiply the second fraction by 7

1×37×3+1×73×7=321+721 \frac{1\times3}{7\times3}+\frac{1\times7}{3\times7}=\frac{3}{21}+\frac{7}{21}

Now we'll combine and get:

3+721=1021 \frac{3+7}{21}=\frac{10}{21}

Answer

1021 \frac{10}{21}

Exercise #13

Solve the following exercise:

25+13= \frac{2}{5}+\frac{1}{3}=

Video Solution

Step-by-Step Solution

Let's try to find the lowest common denominator between 5 and 3

To find the lowest common denominator, we need to find a number that is divisible by both 5 and 3

In this case, the common denominator is 15

Now we'll multiply each fraction by the appropriate number to reach the denominator 15

We'll multiply the first fraction by 3

We'll multiply the second fraction by 5

2×35×3+1×53×5=615+515 \frac{2\times3}{5\times3}+\frac{1\times5}{3\times5}=\frac{6}{15}+\frac{5}{15}

Now we'll combine and get:

6+515=1115 \frac{6+5}{15}=\frac{11}{15}

Answer

1115 \frac{11}{15}

Exercise #14

56+23= \frac{5}{6}+\frac{2}{3}=

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify a common denominator for the fractions.
  • Step 2: Convert the fractions to equivalent fractions with the common denominator.
  • Step 3: Add the fractions by summing the numerators.
  • Step 4: Simplify the resulting fraction if necessary.

Now, let's work through each step:

Step 1: Identify a common denominator.
The denominators of the fractions are 6 and 3.
The least common multiple (LCM) of 6 and 3 is 6.

Step 2: Convert each fraction to equivalent fractions with a common denominator.
56\frac{5}{6} is already expressed with the denominator 6.
To convert 23\frac{2}{3} to a fraction with the denominator 6, we multiply both the numerator and the denominator by 2:
23×22=46\frac{2}{3} \times \frac{2}{2} = \frac{4}{6}.

Step 3: Add the fractions.
Now that both fractions have the same denominator, we can add them:
56+46=96\frac{5}{6} + \frac{4}{6} = \frac{9}{6}.

Step 4: Simplify the resulting fraction.
The fraction 96\frac{9}{6} can be simplified by dividing the numerator and the denominator by their greatest common divisor, which is 3:
96=9÷36÷3=32\frac{9}{6} = \frac{9 \div 3}{6 \div 3} = \frac{3}{2}.

Therefore, the solution to the problem is 32 \frac{3}{2} .

Answer

32 \frac{3}{2}

Exercise #15

Solve the following exercise:

110+13=? \frac{1}{10}+\frac{1}{3}=\text{?}

Video Solution

Step-by-Step Solution

To solve the addition of fractions 110+13 \frac{1}{10} + \frac{1}{3} , we must first find a common denominator.

  • Step 1: Find the Least Common Multiple (LCM) of the denominators, 10 and 3. By multiplying these denominators, the LCM is 10×3=30 10 \times 3 = 30 .

  • Step 2: Rewrite each fraction with the common denominator of 30:
    - Convert 110 \frac{1}{10} to an equivalent fraction with a denominator of 30. Multiply both numerator and denominator by 3: 110=1×310×3=330 \frac{1}{10} = \frac{1 \times 3}{10 \times 3} = \frac{3}{30}
    - Convert 13 \frac{1}{3} to an equivalent fraction with a denominator of 30. Multiply both numerator and denominator by 10: 13=1×103×10=1030 \frac{1}{3} = \frac{1 \times 10}{3 \times 10} = \frac{10}{30}

  • Step 3: Add the equivalent fractions: 330+1030=3+1030=1330 \frac{3}{30} + \frac{10}{30} = \frac{3 + 10}{30} = \frac{13}{30}

  • Step 4: Simplify the resulting fraction. Since 13 is a prime number and does not divide 30, 1330\frac{13}{30} is already in its simplest form.

Thus, the sum of 110 \frac{1}{10} and 13 \frac{1}{3} is 1330 \frac{13}{30} .

The correct answer is 1330 \frac{13}{30} , which corresponds to choice 4.

Answer

1330 \frac{13}{30}

Exercise #16

Solve the following exercise:

12+19=? \frac{1}{2}+\frac{1}{9}=\text{?}

Video Solution

Step-by-Step Solution

To solve this problem, we will add the fractions 12 \frac{1}{2} and 19 \frac{1}{9} by finding a common denominator.

  • First, identify the denominators: 2 and 9.
  • Find a common denominator by multiplying the denominators: 2×9=18 2 \times 9 = 18 .
  • Convert each fraction to an equivalent fraction with this common denominator:
    • Convert 12 \frac{1}{2} to have a denominator of 18 by multiplying both the numerator and denominator by 9: 1×92×9=918 \frac{1 \times 9}{2 \times 9} = \frac{9}{18} .
    • Convert 19 \frac{1}{9} to have a denominator of 18 by multiplying both the numerator and denominator by 2: 1×29×2=218 \frac{1 \times 2}{9 \times 2} = \frac{2}{18} .
  • Add the converted fractions: 918+218=1118 \frac{9}{18} + \frac{2}{18} = \frac{11}{18} .
  • The fraction 1118 \frac{11}{18} is already in its simplest form.

Thus, the sum of the fractions 12 \frac{1}{2} and 19 \frac{1}{9} is 1118 \frac{11}{18} .

Answer

1118 \frac{11}{18}

Exercise #17

Solve the following exercise:

12+25=? \frac{1}{2}+\frac{2}{5}=\text{?}

Video Solution

Step-by-Step Solution

To solve the problem of adding the fractions 12 \frac{1}{2} and 25 \frac{2}{5} , we will follow these steps:

  • Step 1: Determine a common denominator for the fractions.
  • Step 2: Convert each fraction to an equivalent fraction with this common denominator.
  • Step 3: Add the resulting fractions.

Now, let’s explore each step in detail:

Step 1: The denominators are 2 and 5. A common denominator can be found by multiplying these two numbers: 2×5=10 2 \times 5 = 10 . Therefore, 10 is our common denominator.

Step 2: Convert each fraction to have the common denominator of 10.
- For 12 \frac{1}{2} , multiply both the numerator and the denominator by 5:
12×55=510 \frac{1}{2} \times \frac{5}{5} = \frac{5}{10} .
- For 25 \frac{2}{5} , multiply both the numerator and the denominator by 2:
25×22=410 \frac{2}{5} \times \frac{2}{2} = \frac{4}{10} .

Step 3: Add the fractions 510\frac{5}{10} and 410\frac{4}{10}:
Combine the numerators while keeping the common denominator:
5+4=9 5 + 4 = 9 .
Thus, 510+410=910\frac{5}{10} + \frac{4}{10} = \frac{9}{10} .

Therefore, the sum of 12 \frac{1}{2} and 25 \frac{2}{5} is 910\frac{9}{10}.

Answer

910 \frac{9}{10}

Exercise #18

13+110= \frac{1}{3}+\frac{1}{10}=

Video Solution

Step-by-Step Solution

To solve this problem, we will add the fractions 13 \frac{1}{3} and 110 \frac{1}{10} by finding a common denominator.

  • Step 1: Find a common denominator.
    Since the denominators are 3 and 10, the least common multiple (LCM) of these numbers is 30. Therefore, the common denominator will be 30.
  • Step 2: Convert each fraction to have the common denominator.
    Convert 13 \frac{1}{3} into an equivalent fraction with a denominator of 30:
    13=1×103×10=1030 \frac{1}{3} = \frac{1 \times 10}{3 \times 10} = \frac{10}{30} .
    Convert 110 \frac{1}{10} into an equivalent fraction with a denominator of 30:
    110=1×310×3=330 \frac{1}{10} = \frac{1 \times 3}{10 \times 3} = \frac{3}{30} .
  • Step 3: Add the equivalent fractions.
    Now that both fractions have the same denominator, add the numerators while keeping the denominator 30:
    1030+330=10+330=1330 \frac{10}{30} + \frac{3}{30} = \frac{10 + 3}{30} = \frac{13}{30} .

After calculating, we find that the sum of the fractions is 1330\frac{13}{30}.

Therefore, the correct answer to the problem is 1330 \frac{13}{30} .

Answer

1330 \frac{13}{30}

Exercise #19

13+14= \frac{1}{3}+\frac{1}{4}=

Video Solution

Step-by-Step Solution

To solve this problem, we'll begin by finding a common denominator for the fractions 13 \frac{1}{3} and 14 \frac{1}{4} .
Step 1: Identify the denominators, which are 3 and 4. Multiply these to get a common denominator: 3×4=12 3 \times 4 = 12 .

Step 2: Convert each fraction to an equivalent fraction with the common denominator of 12.

  • To convert 13 \frac{1}{3} to a denominator of 12, multiply both the numerator and the denominator by 4: 1×43×4=412\frac{1 \times 4}{3 \times 4} = \frac{4}{12}.
  • To convert 14 \frac{1}{4} to a denominator of 12, multiply both the numerator and the denominator by 3: 1×34×3=312\frac{1 \times 3}{4 \times 3} = \frac{3}{12}.

Step 3: Add the resulting fractions: 412+312=4+312=712\frac{4}{12} + \frac{3}{12} = \frac{4 + 3}{12} = \frac{7}{12}.

Thus, the sum of 13 \frac{1}{3} and 14 \frac{1}{4} is 712\frac{7}{12}.

Answer

712 \frac{7}{12}

Exercise #20

Solve the following exercise:

13+24=? \frac{1}{3}+\frac{2}{4}=\text{?}

Video Solution

Step-by-Step Solution

To solve this problem, let's follow these steps:

  • Step 1: Simplify the fractions if possible.
  • Step 2: Identify the common denominator.
  • Step 3: Convert each fraction to have this common denominator.
  • Step 4: Add the fractions.
  • Step 5: Simplify the result, if necessary.

Step 1: Simplify 24 \frac{2}{4} . It simplifies to 12 \frac{1}{2} .

Step 2: The denominators are now 3 and 2. Find the least common multiple of 3 and 2, which is 6.

Step 3: Convert each fraction to have the common denominator of 6:
13=1×23×2=26\frac{1}{3} = \frac{1 \times 2}{3 \times 2} = \frac{2}{6}
12=1×32×3=36\frac{1}{2} = \frac{1 \times 3}{2 \times 3} = \frac{3}{6}

Step 4: Add the fractions:
26+36=2+36=56\frac{2}{6} + \frac{3}{6} = \frac{2 + 3}{6} = \frac{5}{6}

Step 5: The fraction 56\frac{5}{6} is already in its simplest form.

Therefore, the solution to the problem is 56\frac{5}{6}.

Answer

1012 \frac{10}{12}