Subtract 45/60 from 21/90
21/90 - 45/60 is -31/60.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 60 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 90 × 2 = 180,
21/90 = 21 × 2/90 × 2 = 42/180 - Likewise, for the 2nd fraction, since 60 × 3 = 180,
45/60 = 45 × 3/60 × 3 = 135/180 - Subtract the two like fractions:
42/180 - 135/180 = 42 - 135/180 = -93/180 - After reducing the fraction, the answer is -31/60
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/90-45/60 21/90-90/60 63/90-45/60