Subtract 21/30 from 3/45
3/45 - 21/30 is -19/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 30 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 45 × 2 = 90,
3/45 = 3 × 2/45 × 2 = 6/90 - Likewise, for the 2nd fraction, since 30 × 3 = 90,
21/30 = 21 × 3/30 × 3 = 63/90 - Subtract the two like fractions:
6/90 - 63/90 = 6 - 63/90 = -57/90 - After reducing the fraction, the answer is -19/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/45-21/30 3/45-42/30 3/90-21/30 3/45-21/60 9/45-21/30 3/45-63/30 3/45-21/90 15/45-21/30 21/45-21/30