Subtract 63/45 from 30/84, Solve 30/84

Subtract 63/45 from 30/84

1^st number: 30/84, 2^nd number: 1 18/45

30/84 - 63/45 is -73/70.

Find the least common denominator or LCM of the two denominators:
LCM of 84 and 45 is 1260

Next, find the equivalent fraction of both fractional numbers with denominator 1260
For the 1st fraction, since 84 × 15 = 1260,
30/84 = 30 × 15/84 × 15 = 450/1260
Likewise, for the 2nd fraction, since 45 × 28 = 1260,
63/45 = 63 × 28/45 × 28 = 1764/1260
Subtract the two like fractions:
450/1260 - 1764/1260 = 450 - 1764/1260 = -1314/1260
After reducing the fraction, the answer is -73/70

MathStep (Works offline)

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