Subtract 20/18 from 42/63
1st number: 42/63, 2nd number: 1 2/18
42/63 - 20/18 is -4/9.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 63 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 63 × 2 = 126,
42/63 = 42 × 2/63 × 2 = 84/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
20/18 = 20 × 7/18 × 7 = 140/126 - Subtract the two like fractions:
84/126 - 140/126 = 84 - 140/126 = -56/126 - After reducing the fraction, the answer is -4/9
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/63-20/18 42/63-40/18 42/63-20/36 42/63-60/18 42/63-20/54 42/63-20/90