Subtract 9/7 from 30/45, Solve 30/45

Subtract 9/7 from 30/45

1^st number: 30/45, 2^nd number: 1 2/7

30/45 - 9/7 is -13/21.

Find the least common denominator or LCM of the two denominators:
LCM of 45 and 7 is 315

Next, find the equivalent fraction of both fractional numbers with denominator 315
For the 1st fraction, since 45 × 7 = 315,
30/45 = 30 × 7/45 × 7 = 210/315
Likewise, for the 2nd fraction, since 7 × 45 = 315,
9/7 = 9 × 45/7 × 45 = 405/315
Subtract the two like fractions:
210/315 - 405/315 = 210 - 405/315 = -195/315
After reducing the fraction, the answer is -13/21

MathStep (Works offline)

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