Subtract 50/21 from 18/42
1st number: 18/42, 2nd number: 2 8/21
18/42 - 50/21 is -41/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
18/42 = 18 × 1/42 × 1 = 18/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
50/21 = 50 × 2/21 × 2 = 100/42 - Subtract the two like fractions:
18/42 - 100/42 = 18 - 100/42 = -82/42 - After reducing the fraction, the answer is -41/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/42-50/21 18/84-50/21 18/42-50/42 54/42-50/21 18/42-50/63 90/42-50/21