Subtract 42/7 from 20/54, Solve 20/54

Subtract 42/7 from 20/54

1^st number: 20/54, 2^nd number: 6 0/7

20/54 - 42/7 is -152/27.

Find the least common denominator or LCM of the two denominators:
LCM of 54 and 7 is 378

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 54 × 7 = 378,
20/54 = 20 × 7/54 × 7 = 140/378
Likewise, for the 2nd fraction, since 7 × 54 = 378,
42/7 = 42 × 54/7 × 54 = 2268/378
Subtract the two like fractions:
140/378 - 2268/378 = 140 - 2268/378 = -2128/378
After reducing the fraction, the answer is -152/27

MathStep (Works offline)

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