Subtract 56/21 from 1/80, Solve 1/80

Subtract 56/21 from 1/80

1^st number: 1/80, 2^nd number: 2 14/21

1/80 - 56/21 is -637/240.

Find the least common denominator or LCM of the two denominators:
LCM of 80 and 21 is 1680

Next, find the equivalent fraction of both fractional numbers with denominator 1680
For the 1st fraction, since 80 × 21 = 1680,
1/80 = 1 × 21/80 × 21 = 21/1680
Likewise, for the 2nd fraction, since 21 × 80 = 1680,
56/21 = 56 × 80/21 × 80 = 4480/1680
Subtract the two like fractions:
21/1680 - 4480/1680 = 21 - 4480/1680 = -4459/1680
After reducing the fraction, the answer is -637/240

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad