Question

If f(x) = 3x^2 - x, find f(-2). 10 14 38

Answer 1

Answer:

f(-2) = 14

Step-by-step explanation:

f(x) = 3x^2 - x

f(-2) = 3(-2)^2 - (-2)

= 3(4) + 2

=12 + 2

= 14

Answer 2

Answer:

f(-2) = 38

Step-by-step explanation:

So what you start with is the variable "x" in 3 different places. When you are changing the x variable, you need to plug it into every variable in the equation. Start by doing that and the problem will look like:

f(-2) = 3(-2)^2 - (-2)

Now you can start with either the 3(-2)^2 or the - (-2), but it is better to go from left to right. So simplify the first section:

3 * -2 = -6

-6^2 = -6 * -6 = 36

So now you have:

f(-2) = 36 - (-2)

Then you should know that when you subtract a negative, it turns into addition. So the new  problem looks like:

f(-2) = 36 + 2

Aka

f(-2) = 38

Hope this helped!

^_^