Answers

Subtract 42/84 from 90/80

1^st number: 1 10/80, 2^nd number: 42/84

90/80 - 42/84 is 5/8.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 80 and 84 is 1680
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1680
2. For the 1st fraction, since 80 × 21 = 1680,
   90/80 = 90 × 21/80 × 21 = 1890/1680
3. Likewise, for the 2nd fraction, since 84 × 20 = 1680,
   42/84 = 42 × 20/84 × 20 = 840/1680
4. Subtract the two like fractions:
   1890/1680 - 840/1680 = 1890 - 840/1680 = 1050/1680
5. After reducing the fraction, the answer is 5/8

MathStep (Works offline)

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

Related:

Subtract Fractions Calculator