Question

Log in baza 2 din (x+2)+log in baza 2 din x=3
Cum se rezolva,va rog ?

Answer 1

$log_{2}(x+2)+ log_{2}x=3 \\ x\ \textgreater \ 0 \\ log_{2}x(x+2)= log_{2}8 \\ x^{2} +2x-8=0 \\ x_{1}= \frac{-2-6}{2}=-4; x_{2}= \frac{-2+6}{2}=2$
S={2}