Subtract 18/80 from 21/15
1st number: 1 6/15, 2nd number: 18/80
21/15 - 18/80 is 47/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 80 is 240
Next, find the equivalent fraction of both fractional numbers with denominator 240 - For the 1st fraction, since 15 × 16 = 240,
21/15 = 21 × 16/15 × 16 = 336/240 - Likewise, for the 2nd fraction, since 80 × 3 = 240,
18/80 = 18 × 3/80 × 3 = 54/240 - Subtract the two like fractions:
336/240 - 54/240 = 336 - 54/240 = 282/240 - After reducing the fraction, the answer is 47/40
- In mixed form: 17/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/15-18/80 21/15-36/80 21/30-18/80 63/15-18/80 21/15-54/80 21/45-18/80 21/15-90/80 21/75-18/80