Subtract 18/36 from 9/42
9/42 - 18/36 is -2/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 36 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 42 × 6 = 252,
9/42 = 9 × 6/42 × 6 = 54/252 - Likewise, for the 2nd fraction, since 36 × 7 = 252,
18/36 = 18 × 7/36 × 7 = 126/252 - Subtract the two like fractions:
54/252 - 126/252 = 54 - 126/252 = -72/252 - After reducing the fraction, the answer is -2/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/42-18/36 9/84-18/36 9/42-18/72 27/42-18/36 9/42-54/36 45/42-18/36 9/42-90/36 63/42-18/36