Add 1/84 and 90/70, Solve 1/84 + 1 20/70 as a fraction

Add 1/84 and 90/70

1^st number: 1/84, 2^nd number: 1 20/70

1/84 + 90/70 is 109/84.

Find the least common denominator or LCM of the two denominators:
LCM of 84 and 70 is 420

Next, find the equivalent fraction of both fractional numbers with denominator 420
For the 1st fraction, since 84 × 5 = 420,
1/84 = 1 × 5/84 × 5 = 5/420
Likewise, for the 2nd fraction, since 70 × 6 = 420,
90/70 = 90 × 6/70 × 6 = 540/420
Add the two like fractions:
5/420 + 540/420 = 5 + 540/420 = 545/420
545/420 simplified gives 109/84
So, 1/84 + 90/70 = 109/84
In mixed form: 125/84

MathStep (Works offline)

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