Subtract 21/90 from 36/80
36/80 - 21/90 is 13/60.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 90 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 80 × 9 = 720,
36/80 = 36 × 9/80 × 9 = 324/720 - Likewise, for the 2nd fraction, since 90 × 8 = 720,
21/90 = 21 × 8/90 × 8 = 168/720 - Subtract the two like fractions:
324/720 - 168/720 = 324 - 168/720 = 156/720 - After reducing the fraction, the answer is 13/60
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/80-21/90 36/80-42/90 36/80-63/90