Subtract 10/42 from 20/80
20/80 - 10/42 is 1/84.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 42 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 80 × 21 = 1680,
20/80 = 20 × 21/80 × 21 = 420/1680 - Likewise, for the 2nd fraction, since 42 × 40 = 1680,
10/42 = 10 × 40/42 × 40 = 400/1680 - Subtract the two like fractions:
420/1680 - 400/1680 = 420 - 400/1680 = 20/1680 - After reducing the fraction, the answer is 1/84
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/80-10/42 20/80-20/42 20/80-10/84 60/80-10/42 20/80-30/42 20/80-50/42 20/80-70/42