Helppp please I don’t get it

A20? -foot ladder is placed against a vertical wall of a? building, with the bottom of the ladder standing on level ground 19 feet from the base of the building. how high up the wall does the ladder? reach?

What is the value of the discriminant of the quadratic equation -2x = -8x + 8 and what does its value mean about thenumber of real number solutions the equation has?

The height of a plant, in inches, p years after planting it is given by the polynomial function r(p) = -2p% + 270p. find the height of the plant when p = 90 years.