SOLUTION: PLEASE HELP!!!"I NEED TO LEARN THESE BEFORE MY TEST ON FRIDAY I have to use the following function for f(0)and f(3) if f(x)=4X+9 AND use the following function for g(x+3)if

Algebra ->  Rational-functions -> SOLUTION: PLEASE HELP!!!"I NEED TO LEARN THESE BEFORE MY TEST ON FRIDAY I have to use the following function for f(0)and f(3) if f(x)=4X+9 AND use the following function for g(x+3)if       Log On


   



Question 801530: PLEASE HELP!!!"I NEED TO LEARN THESE BEFORE MY TEST ON FRIDAY
I have to use the following function for f(0)and f(3) if f(x)=4X+9
AND use the following function for g(x+3)if g(x)=-x^2 +5x+3
These are practice problems I don't know where to begin
Thanks so much in advance

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
have to use the following function for
f(0)and f(3) if f(x)=4X+9
for f(0)= 4x + 9
replace x with 0
f(0) = 4(0) + 9
f(0) = 0 + 9
f(0) = 9
for f(3) = 4x + 9
Replace x with 3
f(3) = 4(3) + 9
f(3) = 12 + 9
f(3) = 21
:
AND use the following function for g(x+3)if g(x)=-x^2 +5x+3
g(x+3) = -x^2 + 5x + 3
Replace x with (x+3)
g(x+3) = -(x+3)^2 + 5(x+3) + 3
FOIL (x+3)(x+3), distribute the 5
g(x+3) = -(x^2 + 6x + 9) + 5x + 15 + 3
removing the brackets with minus in front changes the signs
g(x+3) = -x^2 - 6x - 9 + 5x + 15 + 3
Combine like terms
g(x+3) = -x^2 - x + 9