Subtract 15/90 from 7/80
7/80 - 15/90 is -19/240.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 90 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 80 × 9 = 720,
7/80 = 7 × 9/80 × 9 = 63/720 - Likewise, for the 2nd fraction, since 90 × 8 = 720,
15/90 = 15 × 8/90 × 8 = 120/720 - Subtract the two like fractions:
63/720 - 120/720 = 63 - 120/720 = -57/720 - After reducing the fraction, the answer is -19/240
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/80-15/90 7/80-30/90 21/80-15/90 7/80-45/90 35/80-15/90 7/80-75/90 49/80-15/90