Subtract 30/32 from 21/56, Solve 21/56

Subtract 30/32 from 21/56

21/56 - 30/32 is -9/16.

Find the least common denominator or LCM of the two denominators:
LCM of 56 and 32 is 224

Next, find the equivalent fraction of both fractional numbers with denominator 224
For the 1st fraction, since 56 × 4 = 224,
21/56 = 21 × 4/56 × 4 = 84/224
Likewise, for the 2nd fraction, since 32 × 7 = 224,
30/32 = 30 × 7/32 × 7 = 210/224
Subtract the two like fractions:
84/224 - 210/224 = 84 - 210/224 = -126/224
After reducing the fraction, the answer is -9/16

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad