Odpowiedź :
Odpowiedź:
a) 2.5 b) 9.75
Szczegółowe wyjaśnienie:
a) 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=0.5+2=2.5
b) (x+2){6(x+4)-5(x+6)}=(x+2)(6x+24-5x-30)=(x+2)(x-6)=(-0.5+2)(-0.5-6)=1.5*(-6.5)=
=9.75
a)
[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 = 2,5[/tex]
b)
[tex](x+2)(6(x+4)-5(x+6))=(x+2)(6x+24-5x-30) = (x+2)(x-6) =\\\\=x^{2}-6x+2x-12 = x^{2}-4x-12\\\\\\dla \ \ x = -0,5\\\\x^{2}-4x-12 = (-0,5)^{2}-4\cdot(-0,5)-12 = 0,25+2-12 = -9,75[/tex]