How many distinct positive integer-valued solutions exist to the equation
How many distinct positive integer-valued solutions exist to the equation
Solution
When does ? There are exactly three situations:
The base equals 1: (exponent can be anything)
The base equals -1 and the exponent is even: and is even
The exponent equals 0: (base cannot be 0)
Let's apply this to our equation:
We set the base equal to 1:
We need two numbers that multiply to 10 and add to -7.
Those numbers are -2 and -5.
Solutions: and
We set the base equal to -1:
We need two numbers that multiply to 12 and add to -7.
Those numbers are -3 and -4.
Potential solutions: and
For , the exponent must be even.
When : Exponent = (even)
When : Exponent = (even)
Valid solutions: and
We set the exponent equal to 0:
We need two numbers that multiply to 42 and add to -13.
Those numbers are -6 and -7.
Potential solutions: and
We need to ensure the base isn't 0 (since is undefined).
When : Base = $6^2 - 7(6) + 11 = 36 - 42 + 11 = 5
eq 0$
When : Base = $7^2 - 7(7) + 11 = 49 - 49 + 11 = 11
eq 0$
Valid solutions: and
All distinct positive integer solutions:
From Case 1:
From Case 2:
From Case 3:
Total count: 6 distinct solutions
When solving exponential equations equal to 1, we always check all three cases systematically. This approach ensures we don't miss any solutions.
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