Question

What is 3/4 - 5/7 ?

Answer 1

The solution of $\frac{3}{4} - \frac{5}{7}$ is $\frac{1}{28} \text{ or } 0.0357$

Solution:

Given that we have to find the solution of $\frac{3}{4} - \frac{5}{7}$

To solve the given sum, first make the denominators of both the fractions same

This can be done by taking L.C.M of both denominators

Step 1:

L.C.M of 4 and 7:

The prime factor of 4 = 2 x 2

The prime factor of 7 = 7

For each prime factor, find where it occurs most often as a factor and write it that many times in a new list.

The new superset list is

2, 2, 7

Multiply these factors together to find the LCM

LCM = 2 x 2 x 7 = 28

Thus L.C.M of denominators is 28

Step 2:

Solution of $\frac{3}{4} - \frac{5}{7}$

Multiply the denominator by a number to get 28 and multiply that same number with numerator also

$\frac{3}{4} - \frac{5}{7} = \frac{3 \times 7}{4 \times 7} - \frac{5 \times 4}{7 \times 4}=\frac{21}{28} - \frac{20}{28}\\\\\frac{21}{28} - \frac{20}{28} = \frac{21-20}{28} = \frac{1}{28}\\\\\frac{1}{28} = 0.0357$

Thus solution of $\frac{3}{4} - \frac{5}{7}$ is $\frac{1}{28} \text{ or } 0.0357$