Question

F(x) = 4x^2 + 7x – 18 Find f(-9)

Answer 1

Given :

• f(x) = 4x² + 7x - 18

To Find :

• f(- 9) = ?

Solution :

As, we have f(x) = 4x² + 7x - 18, so to find f(- 9) substitute value of x as (-9).

$\tt : \implies f(-9) = 4(-9)² + 7(-9) - 18$

$\tt : \implies f(-9) = 4 \times 81 + (-63) - 18$

$\tt : \implies f(-9) = 324 - 63 - 18$

$\tt : \implies f(-9) = 324 - 81$

$\tt : \implies f(-9) = 243$

$\Large \underline{\boxed{\bf{f(-9) = 243}}}$

Hence, value of f(- 9) = 243.

Answer 2

Answer:

f(-9) = 243

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

1. Brackets
2. Parenthesis
3. Exponents
4. Multiplication
5. Division
6. Addition
7. Subtraction

• Left to Right

Algebra I

• Function Notations

Step-by-step explanation:

Step 1: Define

f(x) = 4x² + 7x - 18

f(-9) is x = -9

Step 2: Evaluate

1. Substitute in x:                                                                                                f(-9) = 4(-9)² + 7(-9) - 18
2. Evaluate exponents:                                                                                      f(-9) = 4(81) + 7(-9) - 18
3. Multiply:                                                                                                           f(-9) = 324 - 63 - 18
4. Subtract:                                                                                                          f(-9) = 261 - 18
5. Subtract:                                                                                                          f(-9) = 243