Subtract 70/9 from 15/40, Solve 15/40

Subtract 70/9 from 15/40

1^st number: 15/40, 2^nd number: 7 7/9

15/40 - 70/9 is -533/72.

Find the least common denominator or LCM of the two denominators:
LCM of 40 and 9 is 360

Next, find the equivalent fraction of both fractional numbers with denominator 360
For the 1st fraction, since 40 × 9 = 360,
15/40 = 15 × 9/40 × 9 = 135/360
Likewise, for the 2nd fraction, since 9 × 40 = 360,
70/9 = 70 × 40/9 × 40 = 2800/360
Subtract the two like fractions:
135/360 - 2800/360 = 135 - 2800/360 = -2665/360
After reducing the fraction, the answer is -533/72

MathStep (Works offline)

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