Question

Пожалуйста решите систему

Answer 1

$\left \{ {{6x+9-2(4x-9)}\leq 18 \atop {(x-9)^{2}} \geq x^{2}-20x+77 } \right.\\\\\left \{ {{6x+9-8x+18}\leq18\atop {x^{2}-18x+81}\geq x^{2}-20x+77} \right.\\\\\left \{ {{-2x}\leq18-18-9\atop {x^{2}-18x-x^{2}+20x}\geq77-81} \right.\\\\\left \{ {{-2x}\leq-9\atop {2x}\geq-4 } \right. \\\\\left \{ {{x}\geq4,5 \atop {x}\geq-2 } \right.$

Ответ : x ∈ [4,5 ; + ∞)