please help me figure this

Question

select x-coordinate of the vertex of the parabola defined by the function

f(x) = -5x^2 + 9x + 2

Answer 1

for a function y = ax^2 + bx + c
the x-coordinate of the vertex is -b/(2a)

let me know what you got for the x-coordinate

Answer 2

Select the x-coordinate of the vertex of the parabola defined by the function f(x)=-3x^2+7x+8