Subtract 18/20 from 12/45
12/45 - 18/20 is -19/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 45 × 4 = 180,
12/45 = 12 × 4/45 × 4 = 48/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
18/20 = 18 × 9/20 × 9 = 162/180 - Subtract the two like fractions:
48/180 - 162/180 = 48 - 162/180 = -114/180 - After reducing the fraction, the answer is -19/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/45-18/20 12/45-36/20 12/90-18/20 12/45-18/40 36/45-18/20 12/45-54/20 12/45-18/60 60/45-18/20 12/45-90/20 84/45-18/20