Subtract 35/45 from 7/21
7/21 - 35/45 is -4/9.
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,
7/21 = 7 × 15/21 × 15 = 105/315 - Likewise, for the 2nd fraction, since 45 × 7 = 315,
35/45 = 35 × 7/45 × 7 = 245/315 - Subtract the two like fractions:
105/315 - 245/315 = 105 - 245/315 = -140/315 - After reducing the fraction, the answer is -4/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/21-35/45 7/21-70/45 7/42-35/45 7/21-35/90 7/63-35/45 35/21-35/45 49/21-35/45