2 2 2 16*x *y - (3 - 4*x*y)
(16*x^2)*y^2 - (3 - 4*x*y)^2 при y = 4
(16*x^2)*y^2 - (3 - 4*x*y)^2
(16*x^2)*(4)^2 - (3 - 4*x*(4))^2
(16*x^2)*4^2 - (3 - 4*x*4)^2
-(3 - 16*x)^2 + 256*x^2
-(3.0 - 4.0*x*y)^2 + 16.0*x^2*y^2
-9 + 24*x*y
3*(-3 + 8*x*y)