Subtract 21/70 from 84/45, Solve 1 39/45

Subtract 21/70 from 84/45

1^st number: 1 39/45, 2^nd number: 21/70

84/45 - 21/70 is 47/30.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 70 is 630

Next, find the equivalent fraction of both fractional numbers with denominator 630
For the 1st fraction, since 45 × 14 = 630,
84/45 = 84 × 14/45 × 14 = 1176/630
Likewise, for the 2nd fraction, since 70 × 9 = 630,
21/70 = 21 × 9/70 × 9 = 189/630
Subtract the two like fractions:
1176/630 - 189/630 = 1176 - 189/630 = 987/630
After reducing the fraction, the answer is 47/30
In mixed form: 117/30

MathStep (Works offline)

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