Subtract 80/42 from 9/15, Solve 9/15

Subtract 80/42 from 9/15

1^st number: 9/15, 2^nd number: 1 38/42

9/15 - 80/42 is -137/105.

Find the least common denominator or LCM of the two denominators:
LCM of 15 and 42 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 15 × 14 = 210,
9/15 = 9 × 14/15 × 14 = 126/210
Likewise, for the 2nd fraction, since 42 × 5 = 210,
80/42 = 80 × 5/42 × 5 = 400/210
Subtract the two like fractions:
126/210 - 400/210 = 126 - 400/210 = -274/210
After reducing the fraction, the answer is -137/105

MathStep (Works offline)

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