Subtract 21/36 from 21/45
21/45 - 21/36 is -7/60.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 36 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 45 × 4 = 180,
21/45 = 21 × 4/45 × 4 = 84/180 - Likewise, for the 2nd fraction, since 36 × 5 = 180,
21/36 = 21 × 5/36 × 5 = 105/180 - Subtract the two like fractions:
84/180 - 105/180 = 84 - 105/180 = -21/180 - After reducing the fraction, the answer is -7/60
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/45-21/36 21/45-42/36 21/90-21/36 21/45-21/72 63/45-21/36 21/45-63/36