Subtract 45/18 from 21/20
1st number: 1 1/20, 2nd number: 2 9/18
21/20 - 45/18 is -29/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 18 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 20 × 9 = 180,
21/20 = 21 × 9/20 × 9 = 189/180 - Likewise, for the 2nd fraction, since 18 × 10 = 180,
45/18 = 45 × 10/18 × 10 = 450/180 - Subtract the two like fractions:
189/180 - 450/180 = 189 - 450/180 = -261/180 - After reducing the fraction, the answer is -29/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/20-45/18 21/20-90/18 21/40-45/18 21/20-45/36 63/20-45/18 21/60-45/18 21/20-45/54 21/20-45/90