Subtract 70/20 from 21/14, Solve 1 7/14

Subtract 70/20 from 21/14

1^st number: 1 7/14, 2^nd number: 3 10/20

21/14 - 70/20 is -2/1.

Find the least common denominator or LCM of the two denominators:
LCM of 14 and 20 is 140

Next, find the equivalent fraction of both fractional numbers with denominator 140
For the 1st fraction, since 14 × 10 = 140,
21/14 = 21 × 10/14 × 10 = 210/140
Likewise, for the 2nd fraction, since 20 × 7 = 140,
70/20 = 70 × 7/20 × 7 = 490/140
Subtract the two like fractions:
210/140 - 490/140 = 210 - 490/140 = -280/140
After reducing the fraction, the answer is -2/1

MathStep (Works offline)

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