2 2 (x - 3) - x
(x - 3)^2 - x^2 при x = -1/4
(x - 3)^2 - x^2
((-1/4) - 3)^2 - (-1/4)^2
(-1/4 - 3)^2 - (-1/4)^2
21/2
(-3.0 + x)^2 - x^2
9 - 6*x
-3*(-3 + 2*x)