Question

Розвязати систему нерівностей

Answer 1

$\displaystyle\bf\\\left \{ {{20-4x\geq -12} \atop {7x+9>30}} \right. \\\\\\\left \{ {{-4x\geq -12-20} \atop {7x>30-9}} \right. \\\\\\\left \{ {{-4x\geq -32} \atop {7x>21}} \right.\\\\\\\left \{ {{x\leq 8} \atop {x>3}} \right. \\\\\\Otvet:x\in\Big(3 \ ; \ 8\Big]$