Subtract 1/7 from 21/90
21/90 - 1/7 is 19/210.
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,
21/90 = 21 × 7/90 × 7 = 147/630 - Likewise, for the 2nd fraction, since 7 × 90 = 630,
1/7 = 1 × 90/7 × 90 = 90/630 - Subtract the two like fractions:
147/630 - 90/630 = 147 - 90/630 = 57/630 - After reducing the fraction, the answer is 19/210
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/90-1/7 21/90-2/7 21/90-1/14 63/90-1/7 21/90-3/7 21/90-1/21 21/90-5/7 21/90-1/35 21/90-1/49