Subtract 6/45 from 20/21
20/21 - 6/45 is 86/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 21 × 15 = 315,
20/21 = 20 × 15/21 × 15 = 300/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
6/45 = 6 × 7/45 × 7 = 42/315 - Subtract the two like fractions:
300/315 - 42/315 = 300 - 42/315 = 258/315 - After reducing the fraction, the answer is 86/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/21-6/45 20/21-12/45 20/42-6/45 20/21-6/90 60/21-6/45 20/21-18/45 20/63-6/45 20/21-30/45 20/21-42/45