To solve the equation \( x^2 + 9 = 45 \), we first isolate \( x^2 \):
\[
x^2 + 9 = 45
\]
\[
x^2 = 45 - 9
\]
\[
x^2 = 36
\]
Next, we take the square root of both sides:
\[
x = \pm 6
\]
This means the solutions are \( x = 6 \) and \( x = -6 \).
Now, let's review what each person said:
- Trey says the solution is {6}. (Incorrect, as it should include both solutions.)
- Amelia says the solution is {−6, 6}. (Correct, as it includes both solutions.)
- Cho says the solution is {−6}. (Incorrect, as it should include both solutions.)
The correct answer is **Amelia**.