Question

(система)
2^х +у=5
х-2=log_2 y

Answer 1

$\{ { {2^x+y=5} \atop {x-2=log_2 y} }$
$\{ { {2^x=5-y} \atop {2^{x-2}=y} }$
$\{ { {2^x=5-y} \atop {2^x=4y} }$
$5 - y = 4y$
$y = 1$
$2^x=5-1=4$
$x = 2$