Subtract 9/8 from 20/45
1st number: 20/45, 2nd number: 1 1/8
20/45 - 9/8 is -49/72.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 8 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 45 × 8 = 360,
20/45 = 20 × 8/45 × 8 = 160/360 - Likewise, for the 2nd fraction, since 8 × 45 = 360,
9/8 = 9 × 45/8 × 45 = 405/360 - Subtract the two like fractions:
160/360 - 405/360 = 160 - 405/360 = -245/360 - After reducing the fraction, the answer is -49/72
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/45-9/8 20/45-18/8 20/90-9/8 20/45-9/16 60/45-9/8 20/45-27/8 20/45-9/24 20/45-45/8 20/45-9/40 20/45-63/8 20/45-9/56