Solve f(x) = x²: Finding the Input Value When f(?) = 49

To solve this problem, we'll follow these steps:

• Step 1: Identify the given equation from the function.
• Step 2: Use the square root method to find possible values of $x$.
• Step 3: Compare solutions with the provided answer choices.

Now, let's work through each step:
Step 1: Start with the equation $f(x) = 49$ which gives us $x^2 = 49$.
Step 2: Solve for $x$ by taking the square root of both sides, which leads to two possible solutions: $x = \sqrt{49}$ and $x = -\sqrt{49}$. Thus, $x = 7$ or $x = -7$.
Step 3: Compare these solutions with the answer choices:

• $f(7)$
• $f(-7)$
• $f(-3)$ (this is incorrect as $f(-3) = 9$)
• Answers a + b

The correct answers based on the solutions are $f(7)$ and $f(-7)$, making choice 4, "Answers a + b," the correct option.

Therefore, the correct answer is: Answers a + b.