Subtract 45/7 from 42/18
1st number: 2 6/18, 2nd number: 6 3/7
42/18 - 45/7 is -86/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 7 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
42/18 = 42 × 7/18 × 7 = 294/126 - Likewise, for the 2nd fraction, since 7 × 18 = 126,
45/7 = 45 × 18/7 × 18 = 810/126 - Subtract the two like fractions:
294/126 - 810/126 = 294 - 810/126 = -516/126 - After reducing the fraction, the answer is -86/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/18-45/7 42/18-90/7 42/36-45/7 42/18-45/14 42/54-45/7 42/18-45/21 42/90-45/7 42/18-45/35 42/18-45/49