Subtract 15/54 from 6/21, Solve 6/21

Subtract 15/54 from 6/21

6/21 - 15/54 is 1/126.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 54 is 378

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 21 × 18 = 378,
6/21 = 6 × 18/21 × 18 = 108/378
Likewise, for the 2nd fraction, since 54 × 7 = 378,
15/54 = 15 × 7/54 × 7 = 105/378
Subtract the two like fractions:
108/378 - 105/378 = 108 - 105/378 = 3/378
After reducing the fraction, the answer is 1/126

MathStep (Works offline)

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