Question

How to subtract mixed numbers with unlike denominators?.

Answer 1

To subtract mixed numbers with different denominators, follow these steps:

1. Rename the fractions using a common denominator.

2. Subtract whole numbers from whole numbers. You might need to regroup first.

3. Subtract fractions from fractions.

4. Simplify, if needed.

Let's try it with $2\frac{3}{5}-1\frac{1}{4}$

First, rename the fractions using a common denominator. The least common denominator of these fractions is 20. Multiply to make equivalent fractions with 20 as the denominator.

$\frac{3x4}{5x4}=\frac{12}{20}$        $\frac{1x5}{4x5}=\frac{5}{20}$

Rewrite the problem and subtract the whole numbers.

$2\frac{12}{20}-1\frac{5}{20}=1\frac{?}{?}$

Now, subtract the fractions. Subtract the numerators and keep the denominator the same.

$2\frac{12}{20}-1\frac{5}{20}=1\frac{7}{20}$

This answer is already in its simplest form, so there is no need to simplify it.