Subtract 4/64 from 3/21, Solve 3/21

Subtract 4/64 from 3/21

3/21 - 4/64 is 9/112.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 64 is 1344

Next, find the equivalent fraction of both fractional numbers with denominator 1344
For the 1st fraction, since 21 × 64 = 1344,
3/21 = 3 × 64/21 × 64 = 192/1344
Likewise, for the 2nd fraction, since 64 × 21 = 1344,
4/64 = 4 × 21/64 × 21 = 84/1344
Subtract the two like fractions:
192/1344 - 84/1344 = 192 - 84/1344 = 108/1344
After reducing the fraction, the answer is 9/112

MathStep (Works offline)

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