Subtract 42/45 from 20/75
20/75 - 42/45 is -2/3.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 75 and 45 is 225
Next, find the equivalent fraction of both fractional numbers with denominator 225 - For the 1st fraction, since 75 × 3 = 225,
20/75 = 20 × 3/75 × 3 = 60/225 - Likewise, for the 2nd fraction, since 45 × 5 = 225,
42/45 = 42 × 5/45 × 5 = 210/225 - Subtract the two like fractions:
60/225 - 210/225 = 60 - 210/225 = -150/225 - After reducing the fraction, the answer is -2/3
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/75-42/45 20/75-84/45 20/75-42/90 60/75-42/45