Subtract 40/42 from 9/18
9/18 - 40/42 is -19/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 42 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
9/18 = 9 × 7/18 × 7 = 63/126 - Likewise, for the 2nd fraction, since 42 × 3 = 126,
40/42 = 40 × 3/42 × 3 = 120/126 - Subtract the two like fractions:
63/126 - 120/126 = 63 - 120/126 = -57/126 - After reducing the fraction, the answer is -19/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 9/18-80/42 9/36-40/42 9/18-40/84 27/18-40/42 9/54-40/42 45/18-40/42 9/90-40/42 63/18-40/42