Subtract 6/7 from 21/45
21/45 - 6/7 is -41/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 7 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 45 × 7 = 315,
21/45 = 21 × 7/45 × 7 = 147/315 - Likewise, for the 2nd fraction, since 7 × 45 = 315,
6/7 = 6 × 45/7 × 45 = 270/315 - Subtract the two like fractions:
147/315 - 270/315 = 147 - 270/315 = -123/315 - After reducing the fraction, the answer is -41/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/45-6/7 21/45-12/7 21/90-6/7 21/45-6/14 63/45-6/7 21/45-18/7 21/45-6/21 21/45-30/7 21/45-6/35 21/45-42/7 21/45-6/49