Subtract 5/21 from 7/45
7/45 - 5/21 is -26/315.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 45 × 7 = 315,
7/45 = 7 × 7/45 × 7 = 49/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
5/21 = 5 × 15/21 × 15 = 75/315 - Subtract the two like fractions:
49/315 - 75/315 = 49 - 75/315 = -26/315
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/45-5/21 7/45-10/21 7/90-5/21 7/45-5/42 21/45-5/21 7/45-15/21 7/45-5/63 35/45-5/21 7/45-25/21 49/45-5/21 7/45-35/21