Subtract 9/15 from 18/42
18/42 - 9/15 is -6/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 15 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
18/42 = 18 × 5/42 × 5 = 90/210 - Likewise, for the 2nd fraction, since 15 × 14 = 210,
9/15 = 9 × 14/15 × 14 = 126/210 - Subtract the two like fractions:
90/210 - 126/210 = 90 - 126/210 = -36/210 - After reducing the fraction, the answer is -6/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/42-9/15 18/42-18/15 18/84-9/15 18/42-9/30 54/42-9/15 18/42-27/15 18/42-9/45 90/42-9/15 18/42-45/15 18/42-9/75 18/42-63/15