Subtract 7/81 from 18/80
18/80 - 7/81 is 449/3240.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 81 is 6480
Next, find the equivalent fraction of both fractional numbers with denominator 6480 - For the 1st fraction, since 80 × 81 = 6480,
18/80 = 18 × 81/80 × 81 = 1458/6480 - Likewise, for the 2nd fraction, since 81 × 80 = 6480,
7/81 = 7 × 80/81 × 80 = 560/6480 - Subtract the two like fractions:
1458/6480 - 560/6480 = 1458 - 560/6480 = 898/6480 - After reducing the fraction, the answer is 449/3240
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/80-7/81 18/80-14/81 54/80-7/81 18/80-21/81 90/80-7/81 18/80-35/81 18/80-49/81