Subtract 21/5 from 27/90
1st number: 27/90, 2nd number: 4 1/5
27/90 - 21/5 is -39/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 5 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 90 × 1 = 90,
27/90 = 27 × 1/90 × 1 = 27/90 - Likewise, for the 2nd fraction, since 5 × 18 = 90,
21/5 = 21 × 18/5 × 18 = 378/90 - Subtract the two like fractions:
27/90 - 378/90 = 27 - 378/90 = -351/90 - After reducing the fraction, the answer is -39/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 54/90-21/5 27/90-42/5 27/90-21/10 81/90-21/5 27/90-63/5 27/90-21/15 27/90-21/25 27/90-21/35