Subtract 21/7 from 4/90
1st number: 4/90, 2nd number: 3 0/7
4/90 - 21/7 is -133/45.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 7 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
4/90 = 4 × 7/90 × 7 = 28/630 - Likewise, for the 2nd fraction, since 7 × 90 = 630,
21/7 = 21 × 90/7 × 90 = 1890/630 - Subtract the two like fractions:
28/630 - 1890/630 = 28 - 1890/630 = -1862/630 - After reducing the fraction, the answer is -133/45
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/90-21/7 4/90-42/7 4/90-21/14 12/90-21/7 4/90-63/7 20/90-21/7 4/90-21/35 28/90-21/7 4/90-21/49