Respuesta :

y = 2(x-7)(x+9)
y = 2x - 14x (x +9)
y = 2x^2 +18x -14x^2 + 126x
y = -12x^2 +144x
axis of symmetry = -b / 2a
= -144 / 2*-12
= 6
axis of symmetry x = 6