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

Exercise #1

Solve the following exercise:

210+13= \frac{2}{10}+\frac{1}{3}=

Video Solution

Step-by-Step Solution

Let's try to find the least common denominator between 10 and 3

To find the least common denominator, we need to find a number that is divisible by both 10 and 3

In this case, the common denominator is 30

Now we'll multiply each fraction by the appropriate number to reach the denominator 30

We'll multiply the first fraction by 3

We'll multiply the second fraction by 10

2×310×3+1×103×10=630+1030 \frac{2\times3}{10\times3}+\frac{1\times10}{3\times10}=\frac{6}{30}+\frac{10}{30}

Now we'll combine and get:

6+1030=1630 \frac{6+10}{30}=\frac{16}{30}

Answer

1630 \frac{16}{30}

Exercise #2

Solve the following exercise:

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

Video Solution

Step-by-Step Solution

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

To find the least 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 #3

Solve the following exercise:

28+23= \frac{2}{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

2×38×3+2×83×8=624+1624 \frac{2\times3}{8\times3}+\frac{2\times8}{3\times8}=\frac{6}{24}+\frac{16}{24}

Now we'll combine and get:

6+1624=2224 \frac{6+16}{24}=\frac{22}{24}

Answer

2224 \frac{22}{24}

Exercise #4

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 #5

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 #6

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 #7

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 #8

Solve the following exercise:

15+13= \frac{1}{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

1×35×3+1×53×5=315+515 \frac{1\times3}{5\times3}+\frac{1\times5}{3\times5}=\frac{3}{15}+\frac{5}{15}

Now we'll combine and get:

3+515=815 \frac{3+5}{15}=\frac{8}{15}

Answer

815 \frac{8}{15}

Exercise #9

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 #10

Solve the following exercise:

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

Video Solution

Step-by-Step Solution

Let's try to find the lowest common denominator between 5 and 4

To find the lowest common denominator, we need to find a number that is divisible by both 5 and 4

In this case, the common denominator is 20

Now we'll multiply each fraction by the appropriate number to reach the denominator 20

We'll multiply the first fraction by 4

We'll multiply the second fraction by 5

2×45×4+1×54×5=820+520 \frac{2\times4}{5\times4}+\frac{1\times5}{4\times5}=\frac{8}{20}+\frac{5}{20}

Now we'll combine and get:

8+520=1320 \frac{8+5}{20}=\frac{13}{20}

Answer

1320 \frac{13}{20}

Exercise #11

Solve the following exercise:

25+16= \frac{2}{5}+\frac{1}{6}=

Video Solution

Step-by-Step Solution

Let's try to find the lowest common denominator between 5 and 6

To find the lowest common denominator, we need to find a number that is divisible by both 5 and 6

In this case, the common denominator is 30

Now we'll multiply each fraction by the appropriate number to reach the denominator 30

We'll multiply the first fraction by 6

We'll multiply the second fraction by 5

2×65×6+1×56×5=1230+530 \frac{2\times6}{5\times6}+\frac{1\times5}{6\times5}=\frac{12}{30}+\frac{5}{30}

Now we'll combine and get:

12+530=1730 \frac{12+5}{30}=\frac{17}{30}

Answer

1730 \frac{17}{30}

Exercise #12

Solve the following exercise:

25+36= \frac{2}{5}+\frac{3}{6}=

Video Solution

Step-by-Step Solution

Let's try to find the lowest common denominator between 5 and 6

To find the lowest common denominator, we need to find a number that is divisible by both 5 and 6

In this case, the common denominator is 30

Now we'll multiply each fraction by the appropriate number to reach the denominator 30

We'll multiply the first fraction by 6

We'll multiply the second fraction by 5

2×65×6+3×56×5=1230+1530 \frac{2\times6}{5\times6}+\frac{3\times5}{6\times5}=\frac{12}{30}+\frac{15}{30}

Now we'll combine and get:

12+1530=2730 \frac{12+15}{30}=\frac{27}{30}

Answer

2730 \frac{27}{30}

Exercise #13

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 #14

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 #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:

35+14=? \frac{3}{5}+\frac{1}{4}=\text{?}

Video Solution

Step-by-Step Solution

To solve the addition of fractions 35+14 \frac{3}{5} + \frac{1}{4} , follow these steps:

  • Step 1: Find a common denominator. The denominators are 5 and 4. The least common denominator is 20, which is the product of 5 and 4.
  • Step 2: Convert each fraction to have the common denominator of 20.
    • For 35 \frac{3}{5} , multiply both the numerator and the denominator by 4: 35=3×45×4=1220 \frac{3}{5} = \frac{3 \times 4}{5 \times 4} = \frac{12}{20} .
    • For 14 \frac{1}{4} , multiply both the numerator and denominator by 5: 14=1×54×5=520 \frac{1}{4} = \frac{1 \times 5}{4 \times 5} = \frac{5}{20} .
  • Step 3: Add the equivalent fractions: 1220+520=12+520=1720 \frac{12}{20} + \frac{5}{20} = \frac{12 + 5}{20} = \frac{17}{20} .

Thus, the sum of 35 \frac{3}{5} and 14 \frac{1}{4} is 1720 \frac{17}{20} .

Answer

1720 \frac{17}{20}

Exercise #17

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

Video Solution

Step-by-Step Solution

To solve the addition of the fractions 29\frac{2}{9} and 12\frac{1}{2}, follow these steps:

  • Step 1: Determine the Common Denominator.
    The least common denominator for 9 and 2 is 1818 because 9×2=189 \times 2 = 18.
  • Step 2: Adjust Each Fraction.
    Convert 29\frac{2}{9} to a fraction over 18. Multiply both the numerator and the denominator by 2:
    29=2×29×2=418\frac{2}{9} = \frac{2 \times 2}{9 \times 2} = \frac{4}{18}.
    Convert 12\frac{1}{2} to a fraction over 18. Multiply both the numerator and the denominator by 9:
    12=1×92×9=918\frac{1}{2} = \frac{1 \times 9}{2 \times 9} = \frac{9}{18}.
  • Step 3: Add the Fractions.
    Add the resulting fractions: 418+918=4+918=1318\frac{4}{18} + \frac{9}{18} = \frac{4 + 9}{18} = \frac{13}{18}.

Thus, the sum of 29\frac{2}{9} and 12\frac{1}{2} is 1318\frac{13}{18}.

Answer

1318 \frac{13}{18}

Exercise #18

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 #19

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 #20

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}