Subtract 90/7 from 90/9
1st number: 10 0/9, 2nd number: 12 6/7
90/9 - 90/7 is -20/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 7 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 9 × 7 = 63,
90/9 = 90 × 7/9 × 7 = 630/63 - Likewise, for the 2nd fraction, since 7 × 9 = 63,
90/7 = 90 × 9/7 × 9 = 810/63 - Subtract the two like fractions:
630/63 - 810/63 = 630 - 810/63 = -180/63 - After reducing the fraction, the answer is -20/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/18-90/7 90/9-90/14 90/27-90/7 90/9-90/21 90/45-90/7 90/9-90/35 90/63-90/7 90/9-90/49