Subtract 12/40 from 20/72
20/72 - 12/40 is -1/45.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 40 is 360
Next, find the equivalent fraction of both fractional numbers with denominator 360 - For the 1st fraction, since 72 × 5 = 360,
20/72 = 20 × 5/72 × 5 = 100/360 - Likewise, for the 2nd fraction, since 40 × 9 = 360,
12/40 = 12 × 9/40 × 9 = 108/360 - Subtract the two like fractions:
100/360 - 108/360 = 100 - 108/360 = -8/360 - After reducing the fraction, the answer is -1/45
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 40/72-12/40 20/72-24/40 20/72-12/80 60/72-12/40 20/72-36/40 20/72-60/40 20/72-84/40