Subtract 63/21 from 81/60, Solve 1 21/60

Subtract 63/21 from 81/60

1^st number: 1 21/60, 2^nd number: 3 0/21

81/60 - 63/21 is -33/20.

Find the least common denominator or LCM of the two denominators:
LCM of 60 and 21 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 60 × 7 = 420,
81/60 = 81 × 7/60 × 7 = 567/420
Likewise, for the 2nd fraction, since 21 × 20 = 420,
63/21 = 63 × 20/21 × 20 = 1260/420
Subtract the two like fractions:
567/420 - 1260/420 = 567 - 1260/420 = -693/420
After reducing the fraction, the answer is -33/20

MathStep (Works offline)

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