Subtract 84/18 from 40/21
1st number: 1 19/21, 2nd number: 4 12/18
40/21 - 84/18 is -58/21.
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,
40/21 = 40 × 6/21 × 6 = 240/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
84/18 = 84 × 7/18 × 7 = 588/126 - Subtract the two like fractions:
240/126 - 588/126 = 240 - 588/126 = -348/126 - After reducing the fraction, the answer is -58/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/21-84/18 40/42-84/18 40/21-84/36 40/63-84/18 40/21-84/54 40/21-84/90