Subtract 28/36 from 20/42
20/42 - 28/36 is -19/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 36 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 42 × 6 = 252,
20/42 = 20 × 6/42 × 6 = 120/252 - Likewise, for the 2nd fraction, since 36 × 7 = 252,
28/36 = 28 × 7/36 × 7 = 196/252 - Subtract the two like fractions:
120/252 - 196/252 = 120 - 196/252 = -76/252 - After reducing the fraction, the answer is -19/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/42-28/36 20/42-56/36 20/84-28/36 20/42-28/72 60/42-28/36 20/42-84/36