Odpowiedź :
Obliczenia
[tex]x^2-(x+2)(x-1)=x^2-(x^2-x+2x-2)=\\\\=x^2-(x^2+x-2)=x^2-x^2-x+2=-x+2\\\\dla \ x=-0,5\\\\-x+2=-(-0,5)+2=0,5+2=\boxed{2,5}[/tex]
Obliczenia
[tex]x^2-(x+2)(x-1)=x^2-(x^2-x+2x-2)=\\\\=x^2-(x^2+x-2)=x^2-x^2-x+2=-x+2\\\\dla \ x=-0,5\\\\-x+2=-(-0,5)+2=0,5+2=\boxed{2,5}[/tex]