Subtract 20/90 from 21/15
1st number: 1 6/15, 2nd number: 20/90
21/15 - 20/90 is 53/45.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 90 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 15 × 6 = 90,
21/15 = 21 × 6/15 × 6 = 126/90 - Likewise, for the 2nd fraction, since 90 × 1 = 90,
20/90 = 20 × 1/90 × 1 = 20/90 - Subtract the two like fractions:
126/90 - 20/90 = 126 - 20/90 = 106/90 - After reducing the fraction, the answer is 53/45
- In mixed form: 18/45
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15-20/90 21/15-40/90 21/30-20/90 63/15-20/90 21/15-60/90 21/45-20/90 21/75-20/90