For the function `f` given by `f(x)=x^2-6x+8` , prove that `f\ '\ (5)-3\ f\ '\ (2)=f\ '\ (8)` .

Explanation

To prove that \( f'(5) - 3f'(2) = f'(8) \) for the function \( f(x) = x^2 - 6x + 8 \), we will follow these steps:

### Step 1: Find the derivative of \( f(x) \)

The function is given by:
\[ f(x) = x^2 - 6x + 8 \]
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