Subtract 90/21 from 10/40
1st number: 10/40, 2nd number: 4 6/21
10/40 - 90/21 is -113/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
10/40 = 10 × 21/40 × 21 = 210/840 - Likewise, for the 2nd fraction, since 21 × 40 = 840,
90/21 = 90 × 40/21 × 40 = 3600/840 - Subtract the two like fractions:
210/840 - 3600/840 = 210 - 3600/840 = -3390/840 - After reducing the fraction, the answer is -113/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/40-90/21 10/80-90/21 10/40-90/42 30/40-90/21 10/40-90/63 50/40-90/21 70/40-90/21