If `f(x) = 9x^(2) + 5x - 8`, then `f(-2)` = ?

Options

A. `-54`
B. `-18`
C. `18`
D. 36

Answer

To find \( f(-2) \) for the function \( f(x) = 9x^2 + 5x - 8 \), we will substitute \( -2 \) for \( x \) in the function.

### Step-by-step Solution:

1. **Write the function:**
\[ f(x) = 9x^2 + 5x - 8 \]

2. **Substitute \( -2 \) for \( x \):**
\[ f(-2) = 9(-2)^2 + 5(-2) - 8 \]

3. **Calculate \( (-2)^2 \):**
\[ (-2)^2 = 4 \]

4. **Substitute \( 4 \) back into the equation:**
\[ f(-2) = 9(4) + 5(-2) - 8 \]

5. **Calculate \( 9(4) \):**
\[ 9(4) = 36 \]

6. **Calculate \( 5(-2) \):**
\[ 5(-2) = -10 \]

7. **Combine all parts:**
\[ f(-2) = 36 - 10 - 8 \]

8. **Perform the subtraction:**
\[ 36 - 10 = 26 \]
\[ 26 - 8 = 18 \]

9. **Final result:**
\[ f(-2) = 18 \]

### Answer:
Thus, \( f(-2) = 18 \).