Subtract 9/7 from 20/90
1st number: 20/90, 2nd number: 1 2/7
20/90 - 9/7 is -67/63.
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,
20/90 = 20 × 7/90 × 7 = 140/630 - Likewise, for the 2nd fraction, since 7 × 90 = 630,
9/7 = 9 × 90/7 × 90 = 810/630 - Subtract the two like fractions:
140/630 - 810/630 = 140 - 810/630 = -670/630 - After reducing the fraction, the answer is -67/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/90-9/7 20/90-18/7 20/90-9/14 60/90-9/7 20/90-27/7 20/90-9/21 20/90-45/7 20/90-9/35 20/90-63/7 20/90-9/49