Evaluate the expression for the given value of the variable(s).

-x2 - 4x; x = –3
A. 11
B. –1
C. 3
D. –17

Question

Evaluate the expression for the given value of the variable(s).

-x2 - 4x; x = –3
  A. 11 	
  B. –1 	
  C. 3 	
  D. –17

anonymous · Answer

@johnweldon1993

johnweldon1993 · Answer

Alight...so since we are told that x = -3...

All we must do is plug in -3 for every 'x' we see

johnweldon1993 · Answer

So for our equation

$$\large -x^2 - 4x$$

We would replace every 'x' with -3

$$\large -(-3)^2 - 4(-3)$$

what does that come out to?

anonymous · Answer

21? :)

anonymous · Answer

Or idk lol.

muzzack · Answer

Step by step solution :
Step  1  :

Simplify: $\large\ -32  -  4x$

Pull out like factors :

$\large\frak\ -4x - 9  =   -1 • (4x + 9)$ 
Final result :

$\color{green}{\huge\frak\ -1 • (4x + 9)~}$

johnweldon1993 · Answer

Lets see

$$\large -(-3)^2 - 4(-3)$$
Exponents first
$$\large -(9) - 4(-3)$$
Now parenthesis
$$\large -9 - 4(-3)$$
Distribute the 4
$$\large -9 - (-12)$$
$$\large -9 + 12$$
$$\large 3$$

anonymous · Answer

Oh okay i see where i went wrong haha :) thanks :)

johnweldon1993 · Answer

No problem hun :)