Evaluate the expression for the given value of the variable(s). -x 2 - 4x; x = -3?

When x = -3 :
The expression -x² - 4x
= -(-3)² - 4(-3)
= -9 + 12
= 3

The answer is : B. 3

Well,

f(x) = -x^2 - 4X
therefore
f(-3) = - (-3)^2 - 4*(-3)
= -9 + 12
= 3

B. 3 <--- answer

hope it' ll help !!

plug -3 in for x

-(-3)^2-4(-3) = -9 + 12 = 3

　
B. 3

−x²−4x
= −(−3)²−4(−3)
= −9+12
= 3

So x2 being a separate variable, yes? Just use 'y' or some other letter next time.
General form:
-x2 - 4x; x2 is y
-y - 4x; x = -3
-y - 4(-3)
-y + 12

A.
-(11) + 12 = 1

B.
-(3) + 12 = __

You can take it from here. As long as I read x2 correctly, this should go smoothly unless you have any questions.

EDIT:
Ah, you meant x². I should've realized that. You can also write it as x^2 if you don't know how to type ²