Subtract 18/42 from 3/10
3/10 - 18/42 is -9/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 10 and 42 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 10 × 21 = 210,
3/10 = 3 × 21/10 × 21 = 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: 6/10-18/42 3/10-36/42 3/20-18/42 3/10-18/84 9/10-18/42 3/10-54/42 3/30-18/42 15/10-18/42 3/10-90/42 3/50-18/42 21/10-18/42 3/70-18/42