Subtract 27/7 from 18/30, Solve 18/30

Subtract 27/7 from 18/30

1^st number: 18/30, 2^nd number: 3 6/7

18/30 - 27/7 is -114/35.

Find the least common denominator or LCM of the two denominators:
LCM of 30 and 7 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 30 × 7 = 210,
18/30 = 18 × 7/30 × 7 = 126/210
Likewise, for the 2nd fraction, since 7 × 30 = 210,
27/7 = 27 × 30/7 × 30 = 810/210
Subtract the two like fractions:
126/210 - 810/210 = 126 - 810/210 = -684/210
After reducing the fraction, the answer is -114/35

MathStep (Works offline)

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