Subtract 42/64 from 8/21
8/21 - 42/64 is -185/672.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 64 is 1344
Next, find the equivalent fraction of both fractional numbers with denominator 1344 - For the 1st fraction, since 21 × 64 = 1344,
8/21 = 8 × 64/21 × 64 = 512/1344 - Likewise, for the 2nd fraction, since 64 × 21 = 1344,
42/64 = 42 × 21/64 × 21 = 882/1344 - Subtract the two like fractions:
512/1344 - 882/1344 = 512 - 882/1344 = -370/1344 - After reducing the fraction, the answer is -185/672
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/21-42/64 8/21-84/64 8/42-42/64 24/21-42/64 8/63-42/64 40/21-42/64 56/21-42/64