Question

допоможіть даю 50 балів​

Answer 1

Решим систему уравнений: $\displaystyle\left \{ {{2x-5y-7=0} \atop {-x+3y-12=0}} \right. \Leftrightarrow \left \{ {{2x-5y=7} \atop {-x+3y=12~\bigg|*2}} \right. \Rightarrow \\+ \left \{ {{2x-5y=7} \atop {-2x+6y=24}} \right. \\-----------\\y=31\Rightarrow 2x-5*31=7; 2x=7+155; 2x=162;x=81.$

Ответ: $\bf (81;31).$