Subtract 90/80 from 7/42
1st number: 7/42, 2nd number: 1 10/80
7/42 - 90/80 is -23/24.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 80 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 42 × 40 = 1680,
7/42 = 7 × 40/42 × 40 = 280/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
90/80 = 90 × 21/80 × 21 = 1890/1680 - Subtract the two like fractions:
280/1680 - 1890/1680 = 280 - 1890/1680 = -1610/1680 - After reducing the fraction, the answer is -23/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/42-90/80 7/84-90/80 21/42-90/80 35/42-90/80 49/42-90/80