Subtract 3/21 from 21/25, Solve 21/25

Subtract 3/21 from 21/25

21/25 - 3/21 is 122/175.

Find the least common denominator or LCM of the two denominators:
LCM of 25 and 21 is 525

Next, find the equivalent fraction of both fractional numbers with denominator 525
For the 1st fraction, since 25 × 21 = 525,
21/25 = 21 × 21/25 × 21 = 441/525
Likewise, for the 2nd fraction, since 21 × 25 = 525,
3/21 = 3 × 25/21 × 25 = 75/525
Subtract the two like fractions:
441/525 - 75/525 = 441 - 75/525 = 366/525
After reducing the fraction, the answer is 122/175

MathStep (Works offline)

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