solve.
x^2-15x+50
(x-5)(x+10)
(x+5)(x+10)
(x-10)(x-5)
(x-10)(x+5)
x^2-15x+50
(x-5)(x+10)
(x+5)(x+10)
(x-10)(x-5)
(x-10)(x+5)
