How do I know if the points (2,-15) lie on a parabola which has the equation y=x^2-6x-7?
(2,-15), Y = X^2 - 6X -7.
When 2 is plugged into the equation,
you should get Y = -15 which proves that the point is on the parabola.
Y = 2^2 - 6 (2) -7 = -15