Subtract 8/21 from 56/8, Solve 7 0/8

Subtract 8/21 from 56/8

1^st number: 7 0/8, 2^nd number: 8/21

56/8 - 8/21 is 139/21.

Find the least common denominator or LCM of the two denominators:
LCM of 8 and 21 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 8 × 21 = 168,
56/8 = 56 × 21/8 × 21 = 1176/168
Likewise, for the 2nd fraction, since 21 × 8 = 168,
8/21 = 8 × 8/21 × 8 = 64/168
Subtract the two like fractions:
1176/168 - 64/168 = 1176 - 64/168 = 1112/168
After reducing the fraction, the answer is 139/21
In mixed form: 613/21

MathStep (Works offline)

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