Subtract 90/84 from 20/30
1st number: 20/30, 2nd number: 1 6/84
20/30 - 90/84 is -17/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 84 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 30 × 14 = 420,
20/30 = 20 × 14/30 × 14 = 280/420 - Likewise, for the 2nd fraction, since 84 × 5 = 420,
90/84 = 90 × 5/84 × 5 = 450/420 - Subtract the two like fractions:
280/420 - 450/420 = 280 - 450/420 = -170/420 - After reducing the fraction, the answer is -17/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/30-90/84 20/60-90/84 60/30-90/84 20/90-90/84