Subtract 42/18 from 72/7, Solve 10 2/7

Subtract 42/18 from 72/7

1^st number: 10 2/7, 2^nd number: 2 6/18

72/7 - 42/18 is 167/21.

Find the least common denominator or LCM of the two denominators:
LCM of 7 and 18 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 7 × 18 = 126,
72/7 = 72 × 18/7 × 18 = 1296/126
Likewise, for the 2nd fraction, since 18 × 7 = 126,
42/18 = 42 × 7/18 × 7 = 294/126
Subtract the two like fractions:
1296/126 - 294/126 = 1296 - 294/126 = 1002/126
After reducing the fraction, the answer is 167/21
In mixed form: 720/21

MathStep (Works offline)

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