Subtract 8/42 from 80/70, Solve 1 10/70

Subtract 8/42 from 80/70

1^st number: 1 10/70, 2^nd number: 8/42

80/70 - 8/42 is 20/21.

Find the least common denominator or LCM of the two denominators:
LCM of 70 and 42 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 70 × 3 = 210,
80/70 = 80 × 3/70 × 3 = 240/210
Likewise, for the 2nd fraction, since 42 × 5 = 210,
8/42 = 8 × 5/42 × 5 = 40/210
Subtract the two like fractions:
240/210 - 40/210 = 240 - 40/210 = 200/210
After reducing the fraction, the answer is 20/21

MathStep (Works offline)

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