Subtract 45/24 from 15/21, Solve 15/21

Subtract 45/24 from 15/21

1^st number: 15/21, 2^nd number: 1 21/24

15/21 - 45/24 is -65/56.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 24 is 168

Next, find the equivalent fraction of both fractional numbers with denominator 168
For the 1st fraction, since 21 × 8 = 168,
15/21 = 15 × 8/21 × 8 = 120/168
Likewise, for the 2nd fraction, since 24 × 7 = 168,
45/24 = 45 × 7/24 × 7 = 315/168
Subtract the two like fractions:
120/168 - 315/168 = 120 - 315/168 = -195/168
After reducing the fraction, the answer is -65/56

MathStep (Works offline)

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