Subtract 21/54 from 12/90
12/90 - 21/54 is -23/90.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 54 is 270
Next, find the equivalent fraction of both fractional numbers with denominator 270 - For the 1st fraction, since 90 × 3 = 270,
12/90 = 12 × 3/90 × 3 = 36/270 - Likewise, for the 2nd fraction, since 54 × 5 = 270,
21/54 = 21 × 5/54 × 5 = 105/270 - Subtract the two like fractions:
36/270 - 105/270 = 36 - 105/270 = -69/270 - After reducing the fraction, the answer is -23/90
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/90-21/54 12/90-42/54 36/90-21/54 12/90-63/54 60/90-21/54 84/90-21/54