Subtract 81/32 from 42/84
1st number: 42/84, 2nd number: 2 17/32
42/84 - 81/32 is -65/32.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 32 is 672
Next, find the equivalent fraction of both fractional numbers with denominator 672 - For the 1st fraction, since 84 × 8 = 672,
42/84 = 42 × 8/84 × 8 = 336/672 - Likewise, for the 2nd fraction, since 32 × 21 = 672,
81/32 = 81 × 21/32 × 21 = 1701/672 - Subtract the two like fractions:
336/672 - 1701/672 = 336 - 1701/672 = -1365/672 - After reducing the fraction, the answer is -65/32
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/84-81/64 42/84-81/96