Add 40/12 and 75/70, Solve 3 4/12 + 1 5/70 as a fraction

Add 40/12 and 75/70

1^st number: 3 4/12, 2^nd number: 1 5/70

40/12 + 75/70 is 185/42.

Find the least common denominator or LCM of the two denominators:
LCM of 12 and 70 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 12 × 35 = 420,
40/12 = 40 × 35/12 × 35 = 1400/420
Likewise, for the 2nd fraction, since 70 × 6 = 420,
75/70 = 75 × 6/70 × 6 = 450/420
Add the two like fractions:
1400/420 + 450/420 = 1400 + 450/420 = 1850/420
1850/420 simplified gives 185/42
So, 40/12 + 75/70 = 185/42
In mixed form: 417/42

MathStep (Works offline)

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