Subtract 75/70 from 70/21, Solve 3 7/21

Subtract 75/70 from 70/21

1^st number: 3 7/21, 2^nd number: 1 5/70

70/21 - 75/70 is 95/42.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 70 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 21 × 10 = 210,
70/21 = 70 × 10/21 × 10 = 700/210
Likewise, for the 2nd fraction, since 70 × 3 = 210,
75/70 = 75 × 3/70 × 3 = 225/210
Subtract the two like fractions:
700/210 - 225/210 = 700 - 225/210 = 475/210
After reducing the fraction, the answer is 95/42
In mixed form: 211/42

MathStep (Works offline)

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