Subtract 21/8 from 15/63, Solve 15/63

Subtract 21/8 from 15/63

1^st number: 15/63, 2^nd number: 2 5/8

15/63 - 21/8 is -401/168.

Find the least common denominator or LCM of the two denominators:
LCM of 63 and 8 is 504

Next, find the equivalent fraction of both fractional numbers with denominator 504
For the 1st fraction, since 63 × 8 = 504,
15/63 = 15 × 8/63 × 8 = 120/504
Likewise, for the 2nd fraction, since 8 × 63 = 504,
21/8 = 21 × 63/8 × 63 = 1323/504
Subtract the two like fractions:
120/504 - 1323/504 = 120 - 1323/504 = -1203/504
After reducing the fraction, the answer is -401/168

MathStep (Works offline)

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