Solve the Fraction Subtraction: 5/4 - 3/8 Step-by-Step

Question

Solve the following exercise:

5438=? \frac{5}{4}-\frac{3}{8}=\text{?}

Video Solution

Solution Steps

00:00 Solve
00:03 Multiply the fraction by 2 to get to the common denominator
00:07 Make sure to multiply both numerator and denominator
00:14 Calculate the multiplications
00:19 Subtract with the common denominator
00:26 Calculate the numerator
00:29 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we'll perform the following steps:

  • Step 1: Find the Least Common Denominator (LCD) between 4 4 and 8 8 .
  • Step 2: Convert both fractions to have this common denominator.
  • Step 3: Subtract the numerators, keeping the denominator the same.

Let's apply these steps starting with the first one.

Step 1: Find the Least Common Denominator
The denominators are 4 4 and 8 8 . The least common denominator is the smallest number that both denominators divide into evenly. In this case, the LCD is 8 8 because it is the smallest number that is a multiple of both 4 4 and 8 8 .

Step 2: Convert fractions to have the same denominator of 8 8
- The fraction 54 \frac{5}{4} needs to be converted to a denominator of 8 8 . To do this, multiply both the numerator and denominator by 2 2 :

54×22=108\frac{5}{4} \times \frac{2}{2} = \frac{10}{8}

- The fraction 38 \frac{3}{8} already has the denominator 8 8 , so it remains unchanged as 38 \frac{3}{8} .

Step 3: Subtract the numerators
Now that the fractions have the same denominator, subtract the numerators:

10838=1038=78\frac{10}{8} - \frac{3}{8} = \frac{10 - 3}{8} = \frac{7}{8}

Therefore, the solution to 5438 \frac{5}{4} - \frac{3}{8} is 78\frac{7}{8}.

Answer

78 \frac{7}{8}