Subtract 21/9 from 15/28, Solve 15/28

Subtract 21/9 from 15/28

1^st number: 15/28, 2^nd number: 2 3/9

15/28 - 21/9 is -151/84.

Find the least common denominator or LCM of the two denominators:
LCM of 28 and 9 is 252

Next, find the equivalent fraction of both fractional numbers with denominator 252
For the 1st fraction, since 28 × 9 = 252,
15/28 = 15 × 9/28 × 9 = 135/252
Likewise, for the 2nd fraction, since 9 × 28 = 252,
21/9 = 21 × 28/9 × 28 = 588/252
Subtract the two like fractions:
135/252 - 588/252 = 135 - 588/252 = -453/252
After reducing the fraction, the answer is -151/84

MathStep (Works offline)

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