Subtract 90/20 from 1/42
1st number: 1/42, 2nd number: 4 10/20
1/42 - 90/20 is -94/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 42 × 10 = 420,
1/42 = 1 × 10/42 × 10 = 10/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
90/20 = 90 × 21/20 × 21 = 1890/420 - Subtract the two like fractions:
10/420 - 1890/420 = 10 - 1890/420 = -1880/420 - After reducing the fraction, the answer is -94/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 2/42-90/20 1/84-90/20 1/42-90/40 3/42-90/20 1/42-90/60 5/42-90/20 7/42-90/20