Subtract 81/3 from 12/40, Solve 12/40

Subtract 81/3 from 12/40

1^st number: 12/40, 2^nd number: 27 0/3

12/40 - 81/3 is -267/10.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 3 is 120

Next, find the equivalent fraction of both fractional numbers with denominator 120
For the 1st fraction, since 40 × 3 = 120,
12/40 = 12 × 3/40 × 3 = 36/120
Likewise, for the 2nd fraction, since 3 × 40 = 120,
81/3 = 81 × 40/3 × 40 = 3240/120
Subtract the two like fractions:
36/120 - 3240/120 = 36 - 3240/120 = -3204/120
After reducing the fraction, the answer is -267/10

MathStep (Works offline)

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