Subtract 20/4 from 40/21
1st number: 1 19/21, 2nd number: 5 0/4
40/21 - 20/4 is -65/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 4 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
40/21 = 40 × 4/21 × 4 = 160/84 - Likewise, for the 2nd fraction, since 4 × 21 = 84,
20/4 = 20 × 21/4 × 21 = 420/84 - Subtract the two like fractions:
160/84 - 420/84 = 160 - 420/84 = -260/84 - After reducing the fraction, the answer is -65/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/21-20/4 40/21-40/4 40/42-20/4 40/21-20/8 40/21-60/4 40/63-20/4 40/21-20/12 40/21-20/28