Subtract 40/18 from 45/21
1st number: 2 3/21, 2nd number: 2 4/18
45/21 - 40/18 is -5/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
45/21 = 45 × 6/21 × 6 = 270/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
40/18 = 40 × 7/18 × 7 = 280/126 - Subtract the two like fractions:
270/126 - 280/126 = 270 - 280/126 = -10/126 - After reducing the fraction, the answer is -5/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/21-40/18 45/21-80/18 45/42-40/18 45/21-40/36 45/63-40/18 45/21-40/54 45/21-40/90