Subtract 72/9 from 21/14, Solve 1 7/14

Subtract 72/9 from 21/14

1^st number: 1 7/14, 2^nd number: 8 0/9

21/14 - 72/9 is -13/2.

Find the least common denominator or LCM of the two denominators:
LCM of 14 and 9 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 14 × 9 = 126,
21/14 = 21 × 9/14 × 9 = 189/126
Likewise, for the 2nd fraction, since 9 × 14 = 126,
72/9 = 72 × 14/9 × 14 = 1008/126
Subtract the two like fractions:
189/126 - 1008/126 = 189 - 1008/126 = -819/126
After reducing the fraction, the answer is -13/2

MathStep (Works offline)

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