Subtract 81/15 from 4/40, Solve 4/40

Subtract 81/15 from 4/40

1^st number: 4/40, 2^nd number: 5 6/15

4/40 - 81/15 is -53/10.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 15 is 120

Next, find the equivalent fraction of both fractional numbers with denominator 120
For the 1st fraction, since 40 × 3 = 120,
4/40 = 4 × 3/40 × 3 = 12/120
Likewise, for the 2nd fraction, since 15 × 8 = 120,
81/15 = 81 × 8/15 × 8 = 648/120
Subtract the two like fractions:
12/120 - 648/120 = 12 - 648/120 = -636/120
After reducing the fraction, the answer is -53/10

MathStep (Works offline)

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