SOLUTION: f(x)=-3x^2+5x-1, find f(-2) A. -14 B. -3 C. -23 D. 23

Algebra ->  Linear-equations -> SOLUTION: f(x)=-3x^2+5x-1, find f(-2) A. -14 B. -3 C. -23 D. 23      Log On


   

Question 169787: f(x)=-3x^2+5x-1, find f(-2)
A. -14
B. -3
C. -23
D. 23
Found 2 solutions by jim_thompson5910, Alan3354:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

f%28x%29=-3x%5E2%2B5x-1 Start with the given equation.


f%28-2%29=-3%28-2%29%5E2%2B5%28-2%29-1 Plug in x=-2.


f%28-2%29=-3%284%29%2B5%28-2%29-1 Square -2 to get 4.


f%28-2%29=-12%2B5%28-2%29-1 Multiply -3 and 4 to get -12.


f%28-2%29=-12-10-1 Multiply 5 and -2 to get -10.


f%28-2%29=-23 Combine like terms.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
f(x)=-3x^2+5x-1, find f(-2)
A. -14
B. -3
C. -23
D. 23
-----------------
Sub -2 for x
f(x)=-3x^2+5x-1
f(-2) = -3*(-2)^2 + 5*(-2) -1
= -3*4 -10 -1
= -12 -10 -1
= -23
So it's C