Subtract 6/40 from 63/42, Solve 1 21/42

Subtract 6/40 from 63/42

1^st number: 1 21/42, 2^nd number: 6/40

63/42 - 6/40 is 27/20.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 42 × 20 = 840,
63/42 = 63 × 20/42 × 20 = 1260/840
Likewise, for the 2nd fraction, since 40 × 21 = 840,
6/40 = 6 × 21/40 × 21 = 126/840
Subtract the two like fractions:
1260/840 - 126/840 = 1260 - 126/840 = 1134/840
After reducing the fraction, the answer is 27/20
In mixed form: 17/20

MathStep (Works offline)

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