Subtract 42/98 from 7/90, Solve 7/90

Subtract 42/98 from 7/90

7/90 - 42/98 is -221/630.

Find the least common denominator or LCM of the two denominators:
LCM of 90 and 98 is 4410

Next, find the equivalent fraction of both fractional numbers with denominator 4410
For the 1st fraction, since 90 × 49 = 4410,
7/90 = 7 × 49/90 × 49 = 343/4410
Likewise, for the 2nd fraction, since 98 × 45 = 4410,
42/98 = 42 × 45/98 × 45 = 1890/4410
Subtract the two like fractions:
343/4410 - 1890/4410 = 343 - 1890/4410 = -1547/4410
After reducing the fraction, the answer is -221/630

MathStep (Works offline)

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