Question

Cat face 3 la puterea x+1 + 3 la puterea2-x = 12

Answer 1

$3^{x+1}+ 3^{2-x}=12 \\ 3^{x}*3+9: 3^{x}=12,fie 3^x=t,t\ \textgreater \ 0 \\ 3t+ \frac{9}{t}-12=0 \\ t^2-4t+3=0 \\ t=1;t=3 \\ 3^x=1 deci x=0 \\ 3^x=3 deci x=1$⇒