What is the vertex of the graph of f(x) = x2 + 10x - 9? A) (-5, -34) B) (-5, -9) C) (5, -9) D) (5, 66)

Answer:A) (-5, -34)Step-by-step explanation: f(x) = x^2 + 10x - 9We complete the square to get the equation in vertex formTake the coefficient of the x term and divide by 2 then square it.  We add it and then subtract it not to change the value of the equation f(x) = x^2 + 10x +(10/2)^2 - (10/2)^2 - 9f(x) = x^2 +10x +25 -25 -9f(x) = (x^2 +10x +25) -34The term in parentheses simplified to (x+10/2) ^2      = (x+5)^2 -34    = (x - -5)^2 -34 This is in the form (x-h)^2 +kThe vertex is (h,k)  h=-5 and k=-34(-5,-34)