Subtract 80/45 from 21/8, Solve 2 5/8

Subtract 80/45 from 21/8

1^st number: 2 5/8, 2^nd number: 1 35/45

21/8 - 80/45 is 61/72.

Find the least common denominator or LCM of the two denominators:
LCM of 8 and 45 is 360

Next, find the equivalent fraction of both fractional numbers with denominator 360
For the 1st fraction, since 8 × 45 = 360,
21/8 = 21 × 45/8 × 45 = 945/360
Likewise, for the 2nd fraction, since 45 × 8 = 360,
80/45 = 80 × 8/45 × 8 = 640/360
Subtract the two like fractions:
945/360 - 640/360 = 945 - 640/360 = 305/360
After reducing the fraction, the answer is 61/72

MathStep (Works offline)

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