Subtract 15/90 from 21/56
21/56 - 15/90 is 5/24.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 56 and 90 is 2520
Next, find the equivalent fraction of both fractional numbers with denominator 2520 - For the 1st fraction, since 56 × 45 = 2520,
21/56 = 21 × 45/56 × 45 = 945/2520 - Likewise, for the 2nd fraction, since 90 × 28 = 2520,
15/90 = 15 × 28/90 × 28 = 420/2520 - Subtract the two like fractions:
945/2520 - 420/2520 = 945 - 420/2520 = 525/2520 - After reducing the fraction, the answer is 5/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/56-15/90 21/56-30/90 63/56-15/90 21/56-45/90 21/56-75/90