Subtract 18/45 from 21/18
1st number: 1 3/18, 2nd number: 18/45
21/18 - 18/45 is 23/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 45 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 18 × 5 = 90,
21/18 = 21 × 5/18 × 5 = 105/90 - Likewise, for the 2nd fraction, since 45 × 2 = 90,
18/45 = 18 × 2/45 × 2 = 36/90 - Subtract the two like fractions:
105/90 - 36/90 = 105 - 36/90 = 69/90 - After reducing the fraction, the answer is 23/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/18-18/45 21/18-36/45 21/36-18/45 21/18-18/90 63/18-18/45 21/18-54/45 21/54-18/45 21/18-90/45 21/90-18/45