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Subtracting mixed fractions with unlike denominators

How to subtract mixed fractions with unlike denominators?

Examples of subtracting mixed fractions with unlike denominators

Problem: Subtract mixed fractions with unlike denominators

2213 - 195
1812

Solution.

1. Subtract the whole numbers of the mixed fractions

22 - 19 = 3

2. Subtract the fractions

13 - 5
1812

The denominators are 18 and 12.

The least common multiple of 18 and 12:

lcm(18, 12) = 36

See least common multiple 12 and 18.

The least common multiple is the lowest common denominator of the fractions.

So, the lowest common denominator of the fractions is 36.

Change the first fraction to the lowest common denominator

13 * 2 = 26
18 * 236

Change the second fraction to the lowest common denominator

5 * 3 = 15
12 * 336

Subtract the fractions

26 - 15 = 11
363636

3. Combine the whole and fraction parts

3 + 11 = 311
3636

Answer

2213 - 195 = 311
181236