Subtract 70/80 from 7/90
7/90 - 70/80 is -287/360.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 80 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 90 × 8 = 720,
7/90 = 7 × 8/90 × 8 = 56/720 - Likewise, for the 2nd fraction, since 80 × 9 = 720,
70/80 = 70 × 9/80 × 9 = 630/720 - Subtract the two like fractions:
56/720 - 630/720 = 56 - 630/720 = -574/720 - After reducing the fraction, the answer is -287/360
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/90-70/80 21/90-70/80 35/90-70/80 49/90-70/80