Subtract 28/50 from 42/81
42/81 - 28/50 is -28/675.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 50 is 4050
Next, find the equivalent fraction of both fractional numbers with denominator 4050 - For the 1st fraction, since 81 × 50 = 4050,
42/81 = 42 × 50/81 × 50 = 2100/4050 - Likewise, for the 2nd fraction, since 50 × 81 = 4050,
28/50 = 28 × 81/50 × 81 = 2268/4050 - Subtract the two like fractions:
2100/4050 - 2268/4050 = 2100 - 2268/4050 = -168/4050 - After reducing the fraction, the answer is -28/675
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/81-28/50 42/81-56/50 42/81-84/50