Subtract 90/84 from 36/40, Solve 36/40

Subtract 90/84 from 36/40

1^st number: 36/40, 2^nd number: 1 6/84

36/40 - 90/84 is -6/35.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 84 is 840

Next, find the equivalent fraction of both fractional numbers with denominator 840
For the 1st fraction, since 40 × 21 = 840,
36/40 = 36 × 21/40 × 21 = 756/840
Likewise, for the 2nd fraction, since 84 × 10 = 840,
90/84 = 90 × 10/84 × 10 = 900/840
Subtract the two like fractions:
756/840 - 900/840 = 756 - 900/840 = -144/840
After reducing the fraction, the answer is -6/35

MathStep (Works offline)

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