Question

a)2^(x+2) =16^2
b)4x(x+4)+x=6(1-x)

Answer 1

Răspuns:

a) 6

b) {-6; 1/4}

Explicație pas cu pas:

$a)~2^{x+2}=16^{2},~2^{x+2}=(2^{4}^{2},~2^{x+2}=2^8,~x+2=8,~x=8-2,~x=6\\b)~4x(x+4)+x=6(1-x),~4x^{2}+16x+x=6-6x,~4x^{2}+23x-6=0,~\\delta=23^{2}-4*4*(-6)=529+96=625\\x_{1}=\frac{-23-\sqrt{625} }{8} =\frac{-23-25}{8}=\frac{-48}{8}=-6\\x_{2}=\frac{-23+\sqrt{625} }{8}=\frac{-23+25}{8}=\frac{2}{8}=\frac{1}{4}$