Subtract 3/42 from 12/10, Solve 1 2/10

Subtract 3/42 from 12/10

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

12/10 - 3/42 is 79/70.

Find the least common denominator or LCM of the two denominators:
LCM of 10 and 42 is 210

Next, find the equivalent fraction of both fractional numbers with denominator 210
For the 1st fraction, since 10 × 21 = 210,
12/10 = 12 × 21/10 × 21 = 252/210
Likewise, for the 2nd fraction, since 42 × 5 = 210,
3/42 = 3 × 5/42 × 5 = 15/210
Subtract the two like fractions:
252/210 - 15/210 = 252 - 15/210 = 237/210
After reducing the fraction, the answer is 79/70
In mixed form: 19/70

MathStep (Works offline)

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