РЕШИТЬ!

============ 1 ============
$log_2x \geq 1\\-----------\\ x\ \textgreater \ 0\\ -----------\\ log_2x \geq log_22\\ 2\ \textgreater \ 1 \Rightarrow \\ x \geq 2\\\\ \left \{ {{x\ \textgreater \ 0} \atop {x \geq 2}} \right. \Rightarrow x \geq 2$

Ответ: $x \geq 2$

============ 2 ============

$log_2x \geq 1\\-----------\\ x\ \textgreater \ 0\\ -----------\\ log_2x \leq log_22\\ 2\ \textgreater \ 1 \Rightarrow \\ x \leq 2\\\\ \left \{ {{x\ \textgreater \ 0} \atop {x \leq 2}} \right. \Rightarrow x\in (0;2]$

Ответ: $x\in (0;2]$