Subtract 72/20 from 28/18
1st number: 1 10/18, 2nd number: 3 12/20
28/18 - 72/20 is -92/45.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 20 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 18 × 10 = 180,
28/18 = 28 × 10/18 × 10 = 280/180 - Likewise, for the 2nd fraction, since 20 × 9 = 180,
72/20 = 72 × 9/20 × 9 = 648/180 - Subtract the two like fractions:
280/180 - 648/180 = 280 - 648/180 = -368/180 - After reducing the fraction, the answer is -92/45
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/18-72/20 28/36-72/20 28/18-72/40 84/18-72/20 28/54-72/20 28/18-72/60 28/90-72/20