Subtract 15/21 from 63/45, Solve 1 18/45

Subtract 15/21 from 63/45

1^st number: 1 18/45, 2^nd number: 15/21

63/45 - 15/21 is 24/35.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315

Next, find the equivalent fraction of both fractional numbers with denominator 315
For the 1st fraction, since 45 × 7 = 315,
63/45 = 63 × 7/45 × 7 = 441/315
Likewise, for the 2nd fraction, since 21 × 15 = 315,
15/21 = 15 × 15/21 × 15 = 225/315
Subtract the two like fractions:
441/315 - 225/315 = 441 - 225/315 = 216/315
After reducing the fraction, the answer is 24/35

MathStep (Works offline)

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