x-7<2 x<9<br> -3x<9 x>-3 (при делении на (-3)<0 знак неравенства поменяли)<br>
---------------(-3)\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\(9)----------------------
Ответ: х Є (-3,9) .