If f (x) = 2xsquared-x, find f (-4) - f (9)

-117

Step-by-step explanation:

To find f (-4) - f (9), we must find the values of f (-4) and f (9) first. In order to do that, we'll have to plug in - 4 and 9 individually in the function f (x) = 2x^2-x (or in your words, f (x) - 2xsquared-x).

Let's start with - 4.

f (x) = 2 (-4) ^2 - (-4)

f (x) = 2 (16) + 4

f (x) = 32+4

f (x) = 36

We have the value pf f (-4) now, so let's move on to 9.

f (x) = 2 (9) ^2-9

f (x) = 2 (81) - 9

f (x) = 162-9

f (x) = 153

We have the value of f (9) too now. Let us proceed to find f (-4) - f (9).

Substitute our found values into it.

36-153=-117

-117 is the result of f (-4) - f (9).