Subtract 90/40 from 5/15, Solve 5/15

Subtract 90/40 from 5/15

1^st number: 5/15, 2^nd number: 2 10/40

5/15 - 90/40 is -23/12.

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

Next, find the equivalent fraction of both fractional numbers with denominator 120
For the 1st fraction, since 15 × 8 = 120,
5/15 = 5 × 8/15 × 8 = 40/120
Likewise, for the 2nd fraction, since 40 × 3 = 120,
90/40 = 90 × 3/40 × 3 = 270/120
Subtract the two like fractions:
40/120 - 270/120 = 40 - 270/120 = -230/120
After reducing the fraction, the answer is -23/12

MathStep (Works offline)

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