Subtract 5/21 from 70/45, Solve 1 25/45

Subtract 5/21 from 70/45

1^st number: 1 25/45, 2^nd number: 5/21

70/45 - 5/21 is 83/63.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315

Next, find the equivalent fraction of both fractional numbers with denominator 315
For the 1st fraction, since 45 × 7 = 315,
70/45 = 70 × 7/45 × 7 = 490/315
Likewise, for the 2nd fraction, since 21 × 15 = 315,
5/21 = 5 × 15/21 × 15 = 75/315
Subtract the two like fractions:
490/315 - 75/315 = 490 - 75/315 = 415/315
After reducing the fraction, the answer is 83/63
In mixed form: 120/63

MathStep (Works offline)

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