Subtract 18/21 from 10/45
10/45 - 18/21 is -40/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 45 × 7 = 315,
10/45 = 10 × 7/45 × 7 = 70/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
18/21 = 18 × 15/21 × 15 = 270/315 - Subtract the two like fractions:
70/315 - 270/315 = 70 - 270/315 = -200/315 - After reducing the fraction, the answer is -40/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 20/45-18/21 10/45-36/21 10/90-18/21 10/45-18/42 30/45-18/21 10/45-54/21 10/45-18/63 50/45-18/21 10/45-90/21 70/45-18/21