Subtract 80/84 from 90/27, Solve 3 9/27

Subtract 80/84 from 90/27

1^st number: 3 9/27, 2^nd number: 80/84

90/27 - 80/84 is 50/21.

Find the least common denominator or LCM of the two denominators:
LCM of 27 and 84 is 756

Next, find the equivalent fraction of both fractional numbers with denominator 756
For the 1st fraction, since 27 × 28 = 756,
90/27 = 90 × 28/27 × 28 = 2520/756
Likewise, for the 2nd fraction, since 84 × 9 = 756,
80/84 = 80 × 9/84 × 9 = 720/756
Subtract the two like fractions:
2520/756 - 720/756 = 2520 - 720/756 = 1800/756
After reducing the fraction, the answer is 50/21
In mixed form: 28/21

MathStep (Works offline)

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