Examples with solutions for Addition of Fractions: Multiplication of signed numbers

Exercise #1

38(58)(12)= -\frac{3}{8}-(-\frac{5}{8})-(-\frac{1}{2})=

Video Solution

Step-by-Step Solution

To solve the problem 38(58)(12)-\frac{3}{8}-(-\frac{5}{8})-(-\frac{1}{2}), we will follow these steps:

  • Step 1: Address the negative signs. Note that subtracting a negative is the same as adding its positive counterpart:
    • 38-\frac{3}{8} remains the same.
    • (58)-(-\frac{5}{8}) becomes +58+\frac{5}{8}.
    • (12)-(-\frac{1}{2}) becomes +12+\frac{1}{2}.
  • Step 2: Write the expression with the adjusted signs: 38+58+12-\frac{3}{8} + \frac{5}{8} + \frac{1}{2}.
  • Step 3: Find a common denominator for the fractions. The denominators are 8 and 2. The least common denominator is 8.
  • Step 4: Convert all fractions to have this common denominator:
    • 38-\frac{3}{8} is already with a denominator of 8.
    • 58\frac{5}{8} is already with a denominator of 8.
    • 12=48\frac{1}{2} = \frac{4}{8}.
  • Step 5: Perform the arithmetic operations on the numerators while retaining the common denominator:
  • 38+58+48=3+5+48-\frac{3}{8} + \frac{5}{8} + \frac{4}{8} = \frac{-3+5+4}{8}.
  • Step 6: Compute the result: Calculate 3+5+4=6 -3 + 5 + 4 = 6 , therefore the fraction becomes 68\frac{6}{8}.
  • Step 7: Simplify the fraction 68\frac{6}{8} by dividing both the numerator and the denominator by their greatest common divisor, which is 2:
  • 68=34\frac{6}{8} = \frac{3}{4}.

Therefore, the solution to the problem is 34 \frac{3}{4} .

Answer

34 \frac{3}{4}

Exercise #2

147+(3)12(14)= -\frac{14}{7}+(-3)-\frac{1}{2}-(-\frac{1}{4})=

Video Solution

Step-by-Step Solution

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

  • Step 1: Simplify 147-\frac{14}{7}.
  • Step 2: Perform arithmetic operations in sequence, converting all parts as necessary.
  • Step 3: Combine the fractions into a single fraction and simplify.

Now, let's work through each step:
Step 1: Simplify 147-\frac{14}{7}. Since 14÷7=214 \div 7 = 2, 147=2-\frac{14}{7} = -2.

Step 2: We rewrite the expression properly:
2+(3)12(14)-2 + (-3) - \frac{1}{2} - (-\frac{1}{4}).

Simplify and operate on each part:
Convert 3-3 to a fraction with a denominator of 1: 31-\frac{3}{1}.
Evaluate the subtraction of a negative: (14)=14-(-\frac{1}{4}) = \frac{1}{4}.

Rewrite the expression using fractions:
21+(31)12+14-\frac{2}{1} + (-\frac{3}{1}) - \frac{1}{2} + \frac{1}{4}.

Step 3: Add and subtract the fractions using a common denominator. The least common denominator for 1, 2, and 4 is 4.
21=84-\frac{2}{1} = -\frac{8}{4},
31=124-\frac{3}{1} = -\frac{12}{4},
12=24-\frac{1}{2} = -\frac{2}{4}.

Combining these, we get:
8412424+14=8122+14-\frac{8}{4} - \frac{12}{4} - \frac{2}{4} + \frac{1}{4} = \frac{-8 - 12 - 2 + 1}{4}.

Simplify the numerator: 8122+1=21 -8 - 12 - 2 + 1 = -21.
Thus, we have:
214\frac{-21}{4}.

Therefore, the solution to the problem is 214 -\frac{21}{4} , which corresponds to choice 3.

Answer

214 -\frac{21}{4}

Exercise #3

Solve:

416(38)+28+(14)= -\frac{4}{16}-(-\frac{3}{8})+\frac{2}{8}+(-\frac{1}{4})=

Video Solution

Step-by-Step Solution

To solve the problem, we will follow these steps:

  • Simplify each fraction where possible.
  • Find a common denominator for all fractions.
  • Convert each fraction to have this common denominator.
  • Perform the required operations: subtraction and addition.

Let's begin solving the problem:

Step 1: Simplify each fraction.
- 416-\frac{4}{16} simplifies to 14-\frac{1}{4} since both numerator and denominator can be divided by 4.
- The fractions (38)-(-\frac{3}{8}), 28\frac{2}{8}, and 14-\frac{1}{4} are already in their simplest forms.

Step 2: Find the common denominator.
The denominators are 4 and 8. The least common denominator (LCD) is 8.

Step 3: Convert each fraction to an equivalent fraction with this common denominator:
- 14-\frac{1}{4} becomes 28-\frac{2}{8} because 14×22=28\frac{1}{4} \times \frac{2}{2} = \frac{2}{8}.
- (38)-(-\frac{3}{8}) simplifies to 38\frac{3}{8} (due to subtracting a negative, which makes it positive).
- 28\frac{2}{8} remains unchanged, as it already has the common denominator.
- 14-\frac{1}{4} becomes 28-\frac{2}{8} for the same reason as above.

Step 4: Perform the operations:
28+38+2828-\frac{2}{8} + \frac{3}{8} + \frac{2}{8} - \frac{2}{8}.

Adding and subtracting these fractions with a common denominator:
- Combine them as (2+3+22)/8=1/8(-2 + 3 + 2 - 2)/8 = 1/8.

Therefore, the solution to the problem is 18 \frac{1}{8} .

Answer

18 \frac{1}{8}

Exercise #4

3+(12)+(38)+58= -3+(-\frac{1}{2})+(\frac{3}{8})+\frac{5}{8}=

Video Solution

Step-by-Step Solution

To solve the given problem of adding 3+(12)+38+58 -3 + (-\frac{1}{2}) + \frac{3}{8} + \frac{5}{8} , we will use the following steps:

  • Step 1: Calculate 38+58\frac{3}{8} + \frac{5}{8}
  • Step 2: Subtract 12-\frac{1}{2} from the result of step 1
  • Step 3: Add the final result to 3-3

Now, let us work through each step:

Step 1: Calculate 38+58\frac{3}{8} + \frac{5}{8}. Since these fractions have the same denominator, we simply add their numerators: 3+58=88=1\frac{3 + 5}{8} = \frac{8}{8} = 1.

Step 2: Now we subtract 12-\frac{1}{2} from 1. We can rewrite 11 as 88\frac{8}{8} and 12-\frac{1}{2} as 48-\frac{4}{8} (since their least common denominator is 8). So: 1(12)=88(48)=8+48=128=32.1 - \left(-\frac{1}{2}\right) = \frac{8}{8} - \left(-\frac{4}{8}\right) = \frac{8 + 4}{8} = \frac{12}{8} = \frac{3}{2}.

Step 3: Finally, we add this result to 3-3. 3-3 can be expressed as 62-\frac{6}{2} and 32\frac{3}{2} remains the same: 3+32=62+32=6+32=32=52.-3 + \frac{3}{2} = -\frac{6}{2} + \frac{3}{2} = \frac{-6 + 3}{2} = \frac{-3}{2} = -\frac{5}{2}.

Hence, the solution to the problem is 52-\frac{5}{2}.

Answer

52 -\frac{5}{2}

Exercise #5

12+34+15+(45)= -\frac{1}{2}+\frac{3}{4}+-\frac{1}{5}+(-\frac{4}{5})=

Video Solution

Step-by-Step Solution

To solve this problem, we must simplify the expression 12+34+(15)+(45) -\frac{1}{2} + \frac{3}{4} + (-\frac{1}{5}) + (-\frac{4}{5}) .

First, we need to find the least common denominator (LCD) for the fractions 2, 4, and 5. The LCD is 20.

Next, we convert each fraction to an equivalent fraction with the common denominator of 20:

  • 12-\frac{1}{2} becomes 1020-\frac{10}{20}
  • 34\frac{3}{4} becomes 1520\frac{15}{20}
  • 15-\frac{1}{5} becomes 420-\frac{4}{20}
  • 45-\frac{4}{5} becomes 1620-\frac{16}{20}

Now we perform the addition and subtraction:

1020+15204201620-\frac{10}{20} + \frac{15}{20} - \frac{4}{20} - \frac{16}{20}

Combine the numerators:

10+15416=15-10 + 15 - 4 - 16 = -15

Thus, the resulting fraction is:

1520-\frac{15}{20}

We simplify 1520-\frac{15}{20} by dividing both the numerator and the denominator by their greatest common divisor, which is 5:

1520=34-\frac{15}{20} = -\frac{3}{4}

Therefore, the solution to the problem is 34 -\frac{3}{4} , which corresponds to choice 2.

Answer

34 -\frac{3}{4}

Exercise #6

49+5+(2)+59= -\frac{4}{9}+5+(-2)+\frac{5}{9}=

Video Solution

Step-by-Step Solution

To solve this problem, we'll perform operations involving both fractions and whole numbers:

  • Step 1: Combine the fractional parts 49-\frac{4}{9} and 59\frac{5}{9}.

  • Step 2: Add the remaining whole numbers 55 and 2-2.

  • Step 3: Sum the results from Step 1 and Step 2.

Let's start:
Step 1: Work with the fractions together. - We have 49-\frac{4}{9} and 59\frac{5}{9}, both have the same denominator, thus can be directly added: 49+59=4+59=19 -\frac{4}{9} + \frac{5}{9} = \frac{-4+5}{9} = \frac{1}{9}

Step 2: Add the integer components 55 and 2-2: 5+(2)=52=3. 5 + (-2) = 5 - 2 = 3.

Step 3: Combine results from Step 1 and Step 2: 3+19=279+19=289 3+\frac{1}{9}=\frac{27}{9}+\frac{1}{9}=\frac{28}{9} .

Therefore, the final result of the expression is 289\frac{28}{9}.

Answer

289 \frac{28}{9}

Exercise #7

5+12+10+(34)= -5+-\frac{1}{2}+10+(-\frac{3}{4})=

Video Solution

Step-by-Step Solution

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

  • Step 1: Simplify the integers using addition.
  • Step 2: Simplify the fractions, ensuring a common denominator before adding.
  • Step 3: Combine results from integers and fractions for the final answer.

Let's work through each step:

Step 1: Combine the integers 5 -5 and 10 10 .

5+10=5 -5 + 10 = 5

Step 2: Simplify and add the fractions 12-\frac{1}{2} and 34-\frac{3}{4}.

To add the fractions, we need a common denominator. The denominators are 2 and 4. The least common denominator is 4.

Convert 12-\frac{1}{2} to an equivalent fraction with a denominator of 4:

12=24-\frac{1}{2} = -\frac{2}{4}

Now add 24-\frac{2}{4} and 34-\frac{3}{4}:

24+34=54-\frac{2}{4} + -\frac{3}{4} = -\frac{5}{4}

Step 3: Combine the result of the integer addition and the fraction addition.

The integer result is 5 and the fraction result is 54-\frac{5}{4}. Convert 5 to a fraction with the same denominator:

5=2045 = \frac{20}{4}

Combine the fractions:

204+54=2054=154\frac{20}{4} + -\frac{5}{4} = \frac{20 - 5}{4} = \frac{15}{4}

Therefore, the solution to the problem is 154 \frac{15}{4} .

Answer

154 \frac{15}{4}