Subtract 42/18 from 40/72
1st number: 40/72, 2nd number: 2 6/18
40/72 - 42/18 is -16/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 18 is 72
Next, find the equivalent fraction of both fractional numbers with denominator 72 - For the 1st fraction, since 72 × 1 = 72,
40/72 = 40 × 1/72 × 1 = 40/72 - Likewise, for the 2nd fraction, since 18 × 4 = 72,
42/18 = 42 × 4/18 × 4 = 168/72 - Subtract the two like fractions:
40/72 - 168/72 = 40 - 168/72 = -128/72 - After reducing the fraction, the answer is -16/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 80/72-42/18 40/72-84/18 40/72-42/36 40/72-42/54 40/72-42/90