Subtract 9/4 from 21/18
1st number: 1 3/18, 2nd number: 2 1/4
21/18 - 9/4 is -13/12.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 4 is 36
Next, find the equivalent fraction of both fractional numbers with denominator 36 - For the 1st fraction, since 18 × 2 = 36,
21/18 = 21 × 2/18 × 2 = 42/36 - Likewise, for the 2nd fraction, since 4 × 9 = 36,
9/4 = 9 × 9/4 × 9 = 81/36 - Subtract the two like fractions:
42/36 - 81/36 = 42 - 81/36 = -39/36 - After reducing the fraction, the answer is -13/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18-9/4 21/18-18/4 21/36-9/4 21/18-9/8 63/18-9/4 21/18-27/4 21/54-9/4 21/18-9/12 21/18-45/4 21/90-9/4 21/18-9/20 21/18-63/4 21/18-9/28