Subtract 90/20 from 18/5
1st number: 3 3/5, 2nd number: 4 10/20
18/5 - 90/20 is -9/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 5 and 20 is 20
Next, find the equivalent fraction of both fractional numbers with denominator 20 - For the 1st fraction, since 5 × 4 = 20,
18/5 = 18 × 4/5 × 4 = 72/20 - Likewise, for the 2nd fraction, since 20 × 1 = 20,
90/20 = 90 × 1/20 × 1 = 90/20 - Subtract the two like fractions:
72/20 - 90/20 = 72 - 90/20 = -18/20 - After reducing the fraction, the answer is -9/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/5-90/20 18/10-90/20 18/5-90/40 54/5-90/20 18/15-90/20 18/5-90/60 90/5-90/20 18/25-90/20 18/35-90/20