Subtract 18/72 from 7/2, Solve 3 1/2

Subtract 18/72 from 7/2

1^st number: 3 1/2, 2^nd number: 18/72

7/2 - 18/72 is 13/4.

Find the least common denominator or LCM of the two denominators:
LCM of 2 and 72 is 72

Next, find the equivalent fraction of both fractional numbers with denominator 72
For the 1st fraction, since 2 × 36 = 72,
7/2 = 7 × 36/2 × 36 = 252/72
Likewise, for the 2nd fraction, since 72 × 1 = 72,
18/72 = 18 × 1/72 × 1 = 18/72
Subtract the two like fractions:
252/72 - 18/72 = 252 - 18/72 = 234/72
After reducing the fraction, the answer is 13/4
In mixed form: 31/4

MathStep (Works offline)

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