Start with the equation:
\[
3 \sqrt{x-2} + 1 = 13
\]
Subtract 1 from both sides:
\[
3 \sqrt{x-2} = 12
\]
Then, divide both sides by 3:
\[
\sqrt{x-2} = 4
\]
Step 2: Square Both Sides
Square both sides to eliminate the square root:
\[
x - 2 = 16
\]
Step 3: Solve for \(x\)
Add 2 to both sides to find \(x\):
\[
x = 18
\]
Step 4: Simplify the Expression
Consider the expression:
\[
\frac{-2 \pm \sqrt{-40}}{2}
\]
First, simplify \(\sqrt{-40}\):
\[
\sqrt{-40} = \sqrt{40} \cdot i = \sqrt{4 \cdot 10} \cdot i = 2\sqrt{10} \cdot i
\]
Now substitute back into the expression:
\[
\frac{-2 \pm 2\sqrt{10}i}{2}
\]
This simplifies to:
\[
-1 \pm \sqrt{10}i
\]
Step 5: Final Result
The simplified expression yields two results:
\[
-1 + \sqrt{10}i \quad \text{and} \quad -1 - \sqrt{10}i
\]
Final Answer
For question 10: \( \boxed{x = 18} \)
For question 11: \( -1 \pm \sqrt{10}i \)