Subtract 45/21 from 7/90
1st number: 7/90, 2nd number: 2 3/21
7/90 - 45/21 is -1301/630.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 21 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
7/90 = 7 × 7/90 × 7 = 49/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
45/21 = 45 × 30/21 × 30 = 1350/630 - Subtract the two like fractions:
49/630 - 1350/630 = 49 - 1350/630 = -1301/630
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/90-45/21 7/90-90/21 7/90-45/42 21/90-45/21 7/90-45/63 35/90-45/21 49/90-45/21