Subtract 42/80 from 28/9, Solve 3 1/9

Subtract 42/80 from 28/9

1^st number: 3 1/9, 2^nd number: 42/80

28/9 - 42/80 is 931/360.

Find the least common denominator or LCM of the two denominators:
LCM of 9 and 80 is 720

Next, find the equivalent fraction of both fractional numbers with denominator 720
For the 1st fraction, since 9 × 80 = 720,
28/9 = 28 × 80/9 × 80 = 2240/720
Likewise, for the 2nd fraction, since 80 × 9 = 720,
42/80 = 42 × 9/80 × 9 = 378/720
Subtract the two like fractions:
2240/720 - 378/720 = 2240 - 378/720 = 1862/720
After reducing the fraction, the answer is 931/360
In mixed form: 2211/360

MathStep (Works offline)

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