Subtract 30/20 from 4/42, Solve 4/42

Subtract 30/20 from 4/42

1^st number: 4/42, 2^nd number: 1 10/20

4/42 - 30/20 is -59/42.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 42 × 10 = 420,
4/42 = 4 × 10/42 × 10 = 40/420
Likewise, for the 2nd fraction, since 20 × 21 = 420,
30/20 = 30 × 21/20 × 21 = 630/420
Subtract the two like fractions:
40/420 - 630/420 = 40 - 630/420 = -590/420
After reducing the fraction, the answer is -59/42

MathStep (Works offline)

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