Subtract 15/7 from 21/80
1st number: 21/80, 2nd number: 2 1/7
21/80 - 15/7 is -1053/560.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 7 is 560
Next, find the equivalent fraction of both fractional numbers with denominator 560 - For the 1st fraction, since 80 × 7 = 560,
21/80 = 21 × 7/80 × 7 = 147/560 - Likewise, for the 2nd fraction, since 7 × 80 = 560,
15/7 = 15 × 80/7 × 80 = 1200/560 - Subtract the two like fractions:
147/560 - 1200/560 = 147 - 1200/560 = -1053/560
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/80-15/7 21/80-30/7 21/80-15/14 63/80-15/7 21/80-45/7 21/80-15/21 21/80-75/7 21/80-15/35 21/80-15/49