Subtract 81/24 from 42/2, Solve 21 0/2

Subtract 81/24 from 42/2

1^st number: 21 0/2, 2^nd number: 3 9/24

42/2 - 81/24 is 141/8.

Find the least common denominator or LCM of the two denominators:
LCM of 2 and 24 is 24

Next, find the equivalent fraction of both fractional numbers with denominator 24
For the 1st fraction, since 2 × 12 = 24,
42/2 = 42 × 12/2 × 12 = 504/24
Likewise, for the 2nd fraction, since 24 × 1 = 24,
81/24 = 81 × 1/24 × 1 = 81/24
Subtract the two like fractions:
504/24 - 81/24 = 504 - 81/24 = 423/24
After reducing the fraction, the answer is 141/8
In mixed form: 175/8

MathStep (Works offline)

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