Answers

Subtract 21/81 from 25/84

25/84 - 21/81 is 29/756.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 84 and 81 is 2268
   
   Next, find the equivalent fraction of both fractional numbers with denominator 2268
2. For the 1st fraction, since 84 × 27 = 2268,
   25/84 = 25 × 27/84 × 27 = 675/2268
3. Likewise, for the 2nd fraction, since 81 × 28 = 2268,
   21/81 = 21 × 28/81 × 28 = 588/2268
4. Subtract the two like fractions:
   675/2268 - 588/2268 = 675 - 588/2268 = 87/2268
5. After reducing the fraction, the answer is 29/756

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad

Related: ⁵⁰/₈₄-²¹/₈₁ ²⁵/₈₄-⁴²/₈₁ ⁷⁵/₈₄-²¹/₈₁ ²⁵/₈₄-⁶³/₈₁

Subtract Fractions Calculator