Subtract 15/45 from 21/30
21/30 - 15/45 is 11/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 45 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 30 × 3 = 90,
21/30 = 21 × 3/30 × 3 = 63/90 - Likewise, for the 2nd fraction, since 45 × 2 = 90,
15/45 = 15 × 2/45 × 2 = 30/90 - Subtract the two like fractions:
63/90 - 30/90 = 63 - 30/90 = 33/90 - After reducing the fraction, the answer is 11/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30-15/45 21/30-30/45 21/60-15/45 21/30-15/90 63/30-15/45 21/90-15/45 21/30-75/45