Consider the function f (x) = x2 + 3x - 7. Find the value of f (x) when x = 3 and select the correct answer below.

5

8

11

18

Answer

= 11

Explanation

f (x) = x² + 3x - 7

To get the value of f (x) when x = 3, we substitute x with 3 in the function f (x).

f (x) = x² + 3x - 7

= 3² + (3*3) - 7

= 9 + 9 - 7

= 11

When x = 3, the function f (x) = x² + 3x - 7 has a value of 11.

To find the value of the function when we are given a certain value of x, we need to substitute the value of x (in this case 3) wherever we see it in the function, and then simplify the function like always.

In this function, x appears 2 times, in x² and 3x. Substituting x = 3, we get:

f (x) = (3) ² + 3 (3) - 7

Now we simplify using the order of operations. Exponents:

f (x) = 9 + 3 (3) - 7

Multiplication

f (x) = 9 + 9 - 7

Addition and subtraction

f (x) = 11

That means that f (x) = 11 when x = 3.