Subtract 81/72 from 28/50, Solve 28/50

Subtract 81/72 from 28/50

1^st number: 28/50, 2^nd number: 1 9/72

28/50 - 81/72 is -113/200.

Find the least common denominator or LCM of the two denominators:
LCM of 50 and 72 is 1800

Next, find the equivalent fraction of both fractional numbers with denominator 1800
For the 1st fraction, since 50 × 36 = 1800,
28/50 = 28 × 36/50 × 36 = 1008/1800
Likewise, for the 2nd fraction, since 72 × 25 = 1800,
81/72 = 81 × 25/72 × 25 = 2025/1800
Subtract the two like fractions:
1008/1800 - 2025/1800 = 1008 - 2025/1800 = -1017/1800
After reducing the fraction, the answer is -113/200

MathStep (Works offline)

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