[tex]Zadanie\ 1\\\\W(x)=3x-x^{2} -x^{3}\ \ \ \ dla\ \ x=-3\\\\3\cdot(-3)-(-3)^2-(-3)^3=-9-9-(-27)=-18+27=9 \\\\\\Zadanie\ 2\\\\\frac{2}{x} =\frac{4}{7x-2}\\\\2(7x-2)=4x\\\\14x-4=4x\ \ \mid+4\\\\14x=4x+4\ \ \mid-4x\\\\10x=4\ \ \mid:10\\\\x=0,4\\\\Odp.\ B[/tex]