Subtract 81/63 from 4/12, Solve 4/12

Subtract 81/63 from 4/12

1^st number: 4/12, 2^nd number: 1 18/63

4/12 - 81/63 is -20/21.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 63 is 252

Next, find the equivalent fraction of both fractional numbers with denominator 252
For the 1st fraction, since 12 × 21 = 252,
4/12 = 4 × 21/12 × 21 = 84/252
Likewise, for the 2nd fraction, since 63 × 4 = 252,
81/63 = 81 × 4/63 × 4 = 324/252
Subtract the two like fractions:
84/252 - 324/252 = 84 - 324/252 = -240/252
After reducing the fraction, the answer is -20/21

MathStep (Works offline)

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