Subtract 20/42 from 15/32
15/32 - 20/42 is -5/672.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 32 and 42 is 672
Next, find the equivalent fraction of both fractional numbers with denominator 672 - For the 1st fraction, since 32 × 21 = 672,
15/32 = 15 × 21/32 × 21 = 315/672 - Likewise, for the 2nd fraction, since 42 × 16 = 672,
20/42 = 20 × 16/42 × 16 = 320/672 - Subtract the two like fractions:
315/672 - 320/672 = 315 - 320/672 = -5/672
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/32-20/42 15/32-40/42 15/64-20/42 15/32-20/84 45/32-20/42 15/32-60/42 15/96-20/42 75/32-20/42