Subtract 4/5 from 18/42
18/42 - 4/5 is -13/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 5 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 5 × 42 = 210,
4/5 = 4 × 42/5 × 42 = 168/210 - Subtract the two like fractions:
90/210 - 168/210 = 90 - 168/210 = -78/210 - After reducing the fraction, the answer is -13/35
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/42-4/5 18/42-8/5 18/84-4/5 18/42-4/10 54/42-4/5 18/42-12/5 18/42-4/15 90/42-4/5 18/42-20/5 18/42-4/25 18/42-28/5 18/42-4/35