Find all nonnegative integer solutions of the equation
Solution
We are tasked with finding all nonnegative integer solutions to the equation:
First, we note that because if , the left-hand side would be a fraction, which cannot equal 1.
### Case 1:
The equation simplifies to:
- **Subcase 1.1: **
This implies and , but , so this is not possible.
- **Subcase 1.2: **
The possible solutions are and .
- **Subcase 1.3: **
Taking modulo 4, we get:
Since for , this leads to a contradiction.
### Case 2:
The equation simplifies to:
- **Subcase 2.1: **
The possible solutions are and .
- **Subcase 2.2: **
The possible solutions are and .
- **Subcase 2.3: **
Taking modulo 8, we get:
This implies , which is not possible.
### Case 3:
The equation becomes:
- **Subcase 3.1: **
Taking modulo 4, we get a contradiction for .
- **Subcase 3.2: **
Taking modulo 9, we get a contradiction for .
Thus, we have exhausted all possible cases and find the solutions to be: