Subtract 40/54 from 10/21
10/21 - 40/54 is -50/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 54 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 21 × 18 = 378,
10/21 = 10 × 18/21 × 18 = 180/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
40/54 = 40 × 7/54 × 7 = 280/378 - Subtract the two like fractions:
180/378 - 280/378 = 180 - 280/378 = -100/378 - After reducing the fraction, the answer is -50/189
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/21-40/54 10/21-80/54 10/42-40/54 30/21-40/54 10/63-40/54 50/21-40/54 70/21-40/54