Add 5/12 and 70/42, Solve 5/12 + 1 28/42 as a fraction

Add 5/12 and 70/42

1^st number: 5/12, 2^nd number: 1 28/42

5/12 + 70/42 is 25/12.

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,
5/12 = 5 × 7/12 × 7 = 35/84
Likewise, for the 2nd fraction, since 42 × 2 = 84,
70/42 = 70 × 2/42 × 2 = 140/84
Add the two like fractions:
35/84 + 140/84 = 35 + 140/84 = 175/84
175/84 simplified gives 25/12
So, 5/12 + 70/42 = 25/12
In mixed form: 21/12

MathStep (Works offline)

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