Question

Решите пожалуйста срочно

Answer 1

$\left \{ {{7x+9(3-3x)<45} \atop {6x-18\leq -20}} \right.$

$\left \{ {{7x+27-27x<45} \atop {6x\leq 18-20}} \right.$

$\left \{ {{-20x<45-27} \atop {6x\leq -2}} \right.$

$\left \{ {{-20x<18} \atop {6x:6\leq -2:6}} \right.$

$\left \{ {{-20x:(-20)>18:(-20)} \atop {x\leq -\frac{1}{3} }} \right.$

$\left \{ {{x>-\frac{9}{10} } \atop {x\leq -\frac{1}{3} }} \right.$

$-\frac{9}{10} <x\leq -\frac{1}{3}$

Ответ:   $(-\frac{9}{10}; -\frac{1}{3} ]$