Subtract 40/63 from 20/42
20/42 - 40/63 is -10/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 63 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 42 × 3 = 126,
20/42 = 20 × 3/42 × 3 = 60/126 - Likewise, for the 2nd fraction, since 63 × 2 = 126,
40/63 = 40 × 2/63 × 2 = 80/126 - Subtract the two like fractions:
60/126 - 80/126 = 60 - 80/126 = -20/126 - After reducing the fraction, the answer is -10/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-40/63 20/42-80/63 20/84-40/63 60/42-40/63