Subtract 90/63 from 6/18, Solve 6/18

Subtract 90/63 from 6/18

1^st number: 6/18, 2^nd number: 1 27/63

6/18 - 90/63 is -23/21.

Find the least common denominator or LCM of the two denominators:
LCM of 18 and 63 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 18 × 7 = 126,
6/18 = 6 × 7/18 × 7 = 42/126
Likewise, for the 2nd fraction, since 63 × 2 = 126,
90/63 = 90 × 2/63 × 2 = 180/126
Subtract the two like fractions:
42/126 - 180/126 = 42 - 180/126 = -138/126
After reducing the fraction, the answer is -23/21

MathStep (Works offline)

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