Subtract 81/32 from 30/84, Solve 30/84

Subtract 81/32 from 30/84

1^st number: 30/84, 2^nd number: 2 17/32

30/84 - 81/32 is -487/224.

Find the least common denominator or LCM of the two denominators:
LCM of 84 and 32 is 672

Next, find the equivalent fraction of both fractional numbers with denominator 672
For the 1st fraction, since 84 × 8 = 672,
30/84 = 30 × 8/84 × 8 = 240/672
Likewise, for the 2nd fraction, since 32 × 21 = 672,
81/32 = 81 × 21/32 × 21 = 1701/672
Subtract the two like fractions:
240/672 - 1701/672 = 240 - 1701/672 = -1461/672
After reducing the fraction, the answer is -487/224

MathStep (Works offline)

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