Subtract 21/32 from 18/42
18/42 - 21/32 is -51/224.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 32 is 672
Next, find the equivalent fraction of both fractional numbers with denominator 672 - For the 1st fraction, since 42 × 16 = 672,
18/42 = 18 × 16/42 × 16 = 288/672 - Likewise, for the 2nd fraction, since 32 × 21 = 672,
21/32 = 21 × 21/32 × 21 = 441/672 - Subtract the two like fractions:
288/672 - 441/672 = 288 - 441/672 = -153/672 - After reducing the fraction, the answer is -51/224
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/42-21/32 18/42-42/32 18/84-21/32 18/42-21/64 54/42-21/32 18/42-63/32 18/42-21/96 90/42-21/32