Subtract 9/42 from 7/80
7/80 - 9/42 is -71/560.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 42 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 80 × 21 = 1680,
7/80 = 7 × 21/80 × 21 = 147/1680 - Likewise, for the 2nd fraction, since 42 × 40 = 1680,
9/42 = 9 × 40/42 × 40 = 360/1680 - Subtract the two like fractions:
147/1680 - 360/1680 = 147 - 360/1680 = -213/1680 - After reducing the fraction, the answer is -71/560
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/80-9/42 7/80-18/42 7/80-9/84 21/80-9/42 7/80-27/42 35/80-9/42 7/80-45/42 49/80-9/42 7/80-63/42