Calculate the vertex (h, k) of a parabola from its standard form quadratic equation (y = ax+?+++?G??+?+???+?-?+?G??+?-?+?-?+?G??-?+?Gǣ+?-?+?G??+?-?+?+++?G??+?+???+?-?+?G??+?-++?+++?G??+?+???+?-++???+?-? + bx + c).