y = x^2 + 7x - 4
y = 6x^2 - 7x + 8
y = x^3 + 7x^2 - 2
y = 3x^2 + 7x - 4 + 1/x
y = 3x - 5/x + 6/x^2
y = 5x - 3/sqrt x
(2x + 3) (x + 2)