Subtract 10/42 from 42/12, Solve 3 6/12

Subtract 10/42 from 42/12

1^st number: 3 6/12, 2^nd number: 10/42

42/12 - 10/42 is 137/42.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 42 is 84

Next, find the equivalent fraction of both fractional numbers with denominator 84
For the 1st fraction, since 12 × 7 = 84,
42/12 = 42 × 7/12 × 7 = 294/84
Likewise, for the 2nd fraction, since 42 × 2 = 84,
10/42 = 10 × 2/42 × 2 = 20/84
Subtract the two like fractions:
294/84 - 20/84 = 294 - 20/84 = 274/84
After reducing the fraction, the answer is 137/42
In mixed form: 311/42

MathStep (Works offline)

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