Subtract 12/40 from 90/5, Solve 18 0/5

Subtract 12/40 from 90/5

1^st number: 18 0/5, 2^nd number: 12/40

90/5 - 12/40 is 177/10.

Find the least common denominator or LCM of the two denominators:
LCM of 5 and 40 is 40

Next, find the equivalent fraction of both fractional numbers with denominator 40
For the 1st fraction, since 5 × 8 = 40,
90/5 = 90 × 8/5 × 8 = 720/40
Likewise, for the 2nd fraction, since 40 × 1 = 40,
12/40 = 12 × 1/40 × 1 = 12/40
Subtract the two like fractions:
720/40 - 12/40 = 720 - 12/40 = 708/40
After reducing the fraction, the answer is 177/10
In mixed form: 177/10

MathStep (Works offline)

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