Subtract 27/21 from 36/40, Solve 36/40

Subtract 27/21 from 36/40

1^st number: 36/40, 2^nd number: 1 6/21

36/40 - 27/21 is -27/70.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 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 21 × 40 = 840,
27/21 = 27 × 40/21 × 40 = 1080/840
Subtract the two like fractions:
756/840 - 1080/840 = 756 - 1080/840 = -324/840
After reducing the fraction, the answer is -27/70

MathStep (Works offline)

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