Subtract 80/7 from 30/18, Solve 1 12/18

Subtract 80/7 from 30/18

1^st number: 1 12/18, 2^nd number: 11 3/7

30/18 - 80/7 is -205/21.

Find the least common denominator or LCM of the two denominators:
LCM of 18 and 7 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 18 × 7 = 126,
30/18 = 30 × 7/18 × 7 = 210/126
Likewise, for the 2nd fraction, since 7 × 18 = 126,
80/7 = 80 × 18/7 × 18 = 1440/126
Subtract the two like fractions:
210/126 - 1440/126 = 210 - 1440/126 = -1230/126
After reducing the fraction, the answer is -205/21

MathStep (Works offline)

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