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

Subtract 1/40 from 21/63

21/63 - 1/40 is 37/120.

Find the least common denominator or LCM of the two denominators:
LCM of 63 and 40 is 2520

Next, find the equivalent fraction of both fractional numbers with denominator 2520
For the 1st fraction, since 63 × 40 = 2520,
21/63 = 21 × 40/63 × 40 = 840/2520
Likewise, for the 2nd fraction, since 40 × 63 = 2520,
1/40 = 1 × 63/40 × 63 = 63/2520
Subtract the two like fractions:
840/2520 - 63/2520 = 840 - 63/2520 = 777/2520
After reducing the fraction, the answer is 37/120

MathStep (Works offline)

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