Subtract 45/49 from 21/81
21/81 - 45/49 is -872/1323.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 49 is 3969
Next, find the equivalent fraction of both fractional numbers with denominator 3969 - For the 1st fraction, since 81 × 49 = 3969,
21/81 = 21 × 49/81 × 49 = 1029/3969 - Likewise, for the 2nd fraction, since 49 × 81 = 3969,
45/49 = 45 × 81/49 × 81 = 3645/3969 - Subtract the two like fractions:
1029/3969 - 3645/3969 = 1029 - 3645/3969 = -2616/3969 - After reducing the fraction, the answer is -872/1323
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/81-45/49 21/81-90/49 21/81-45/98 63/81-45/49