SOLUTION: i am trying to find the y coordinate of the vertex. the x is -2 and when i plug it in to the equation i get 3(-2)^2+12(-2)+8 =-28, but the answer is supposed to be -4 can someon

Algebra ->  Algebra  -> Quadratic-relations-and-conic-sections -> SOLUTION: i am trying to find the y coordinate of the vertex. the x is -2 and when i plug it in to the equation i get 3(-2)^2+12(-2)+8 =-28, but the answer is supposed to be -4 can someon      Log On

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Question 229396: i am trying to find the y coordinate of the vertex. the x is -2 and when i plug it in to the equation i get
3(-2)^2+12(-2)+8 =-28, but the answer is supposed to be -4 can someone tell me what i am doing wrong?
Answer by rfer(12730) About Me  (Show Source):
You can put this solution on YOUR website!
I think you lost track of a sign some where.
3(-2)^2+12(-2)+8=
3(+4)-24+8=
12-24+8=
20-24=-4