Subtract 15/7 from 20/30
1st number: 20/30, 2nd number: 2 1/7
20/30 - 15/7 is -31/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 7 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
20/30 = 20 × 7/30 × 7 = 140/210 - Likewise, for the 2nd fraction, since 7 × 30 = 210,
15/7 = 15 × 30/7 × 30 = 450/210 - Subtract the two like fractions:
140/210 - 450/210 = 140 - 450/210 = -310/210 - After reducing the fraction, the answer is -31/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/30-15/7 20/30-30/7 20/60-15/7 20/30-15/14 60/30-15/7 20/30-45/7 20/90-15/7 20/30-15/21 20/30-75/7 20/30-15/35 20/30-15/49