f(x) problem (graphs)

• January 22nd 2008, 07:44 PM
simplekin
f(x) problem (graphs)
If f(x)=-2x+3 and g(x)= 1/2x -8, which statement is true?

A) f(-2)-g(-2)=-2
b) f(-2)-g(-2)= 2
c) f(-2)+g(-2)=-2
D) f(-2)+g(-2)=2

Now i have no idea what to do here, if anyone could explain how they got the answer, it would be appreciated, thank you!
• January 22nd 2008, 07:56 PM
Destiny666
u take -2 and place it in for x or x= -2 meaning about none of those options are correct...
• January 22nd 2008, 08:10 PM
simplekin
in the answers, it says it is C, so.. does anyone have anything else?
• January 23rd 2008, 09:45 AM
topsquark
Using Destiny666's approach I got that answer c) is correct.

$f(-2) + g(-2) = (-2(-2) + 3) + \left ( \frac{1}{2}(-2) - 8 \right )$

$= (4 + 3) + (-1 - 8)$

$= 7 + -9 = -2$

-Dan