Subtract 2/3 from 21/90
21/90 - 2/3 is -13/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 3 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 90 × 1 = 90,
21/90 = 21 × 1/90 × 1 = 21/90 - Likewise, for the 2nd fraction, since 3 × 30 = 90,
2/3 = 2 × 30/3 × 30 = 60/90 - Subtract the two like fractions:
21/90 - 60/90 = 21 - 60/90 = -39/90 - After reducing the fraction, the answer is -13/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/90-2/3 21/90-4/3 21/90-2/6 63/90-2/3 21/90-6/3 21/90-2/9 21/90-10/3 21/90-2/15 21/90-14/3 21/90-2/21