Subtract 18/42 from 9/30
9/30 - 18/42 is -9/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 42 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 30 × 7 = 210,
9/30 = 9 × 7/30 × 7 = 63/210 - Likewise, for the 2nd fraction, since 42 × 5 = 210,
18/42 = 18 × 5/42 × 5 = 90/210 - Subtract the two like fractions:
63/210 - 90/210 = 63 - 90/210 = -27/210 - After reducing the fraction, the answer is -9/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/30-18/42 9/30-36/42 9/60-18/42 9/30-18/84 27/30-18/42 9/30-54/42 9/90-18/42 45/30-18/42 9/30-90/42 63/30-18/42