[tex]zad.3)\\\\x=-\frac{1}{2}\\\\ W(x) =x^3-4x^2+2x-5 =(-\frac{1}{2} )^3 -4*(-\frac{1}{2})^2+\not{2}^1*(-\frac{1}{\not{2}^1})-5=\\\\=-\frac{1}{8}-\not{4}^1*\frac{1}{\not{4}^1}-1-5=-\frac{1}{8}-1-6=-7\frac{1}{8}[/tex]
[tex](a-b)^3 =a^3-3a^2b+3ab^2-b^3\\\\(a+b)^3 =a^3+3a^2b+3ab^2+b^3[/tex]
[tex]zad.4)\\\\a)\\\\(x-2)^3-(x+1)^3=x^3-3x^2*2+3x*2^2-2^3-(a^3+3x^2*1 +3x*1^2+1^2)=\\\\=x^3-6x^2 +12x -8-(a^3+3x^2 +3x +1 )= x^3-6x^2 +12x -8- a^3-3x^2-3x -1=\\\\=-9x^2+9x-9[/tex]
[tex]b)\\\\ (2x-1)(4x^2+2x+1)= 8x^3+ 4x^2+2x - 4x^2-2x-1= 8x^3-1[/tex]
