Subtract 8/7 from 42/2, Solve 21 0/2

Subtract 8/7 from 42/2

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

42/2 - 8/7 is 139/7.

Find the least common denominator or LCM of the two denominators:
LCM of 2 and 7 is 14

Next, find the equivalent fraction of both fractional numbers with denominator 14
For the 1st fraction, since 2 × 7 = 14,
42/2 = 42 × 7/2 × 7 = 294/14
Likewise, for the 2nd fraction, since 7 × 2 = 14,
8/7 = 8 × 2/7 × 2 = 16/14
Subtract the two like fractions:
294/14 - 16/14 = 294 - 16/14 = 278/14
After reducing the fraction, the answer is 139/7
In mixed form: 196/7

MathStep (Works offline)

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