Subtract 5/70 from 84/72, Solve 1 12/72

Subtract 5/70 from 84/72

1^st number: 1 12/72, 2^nd number: 5/70

84/72 - 5/70 is 23/21.

Find the least common denominator or LCM of the two denominators:
LCM of 72 and 70 is 2520

Next, find the equivalent fraction of both fractional numbers with denominator 2520
For the 1st fraction, since 72 × 35 = 2520,
84/72 = 84 × 35/72 × 35 = 2940/2520
Likewise, for the 2nd fraction, since 70 × 36 = 2520,
5/70 = 5 × 36/70 × 36 = 180/2520
Subtract the two like fractions:
2940/2520 - 180/2520 = 2940 - 180/2520 = 2760/2520
After reducing the fraction, the answer is 23/21
In mixed form: 12/21

MathStep (Works offline)

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