Subtract 21/45 from 2/7
2/7 - 21/45 is -19/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 45 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 7 × 45 = 315,
2/7 = 2 × 45/7 × 45 = 90/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
21/45 = 21 × 7/45 × 7 = 147/315 - Subtract the two like fractions:
90/315 - 147/315 = 90 - 147/315 = -57/315 - After reducing the fraction, the answer is -19/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 4/7-21/45 2/7-42/45 2/14-21/45 2/7-21/90 6/7-21/45 2/7-63/45 2/21-21/45 10/7-21/45 2/35-21/45 14/7-21/45 2/49-21/45