Subtract 21/63 from 20/45
20/45 - 21/63 is 1/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 63 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 45 × 7 = 315,
20/45 = 20 × 7/45 × 7 = 140/315 - Likewise, for the 2nd fraction, since 63 × 5 = 315,
21/63 = 21 × 5/63 × 5 = 105/315 - Subtract the two like fractions:
140/315 - 105/315 = 140 - 105/315 = 35/315 - After reducing the fraction, the answer is 1/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/45-21/63 20/45-42/63 20/90-21/63 60/45-21/63