Subtract 10/20 from 21/54
21/54 - 10/20 is -1/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 20 is 540
Next, find the equivalent fraction of both fractional numbers with denominator 540 - For the 1st fraction, since 54 × 10 = 540,
21/54 = 21 × 10/54 × 10 = 210/540 - Likewise, for the 2nd fraction, since 20 × 27 = 540,
10/20 = 10 × 27/20 × 27 = 270/540 - Subtract the two like fractions:
210/540 - 270/540 = 210 - 270/540 = -60/540 - After reducing the fraction, the answer is -1/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/54-10/20 21/54-10/40 63/54-10/20 21/54-30/20 21/54-10/60 21/54-50/20 21/54-70/20