Question

срочно, даю 15 баллов (((((

Answer 1

$\displaystyle 1)\left \{ {{2x+y=11} \atop {5x-2y=41}} \right. \\\\\left \{ {{y=11-2x} \atop {5x-2y=41}} \right.\\ \\5x-2(11-2x)=41\\x=7\\y=11-2*7\\y=-3\\(x,y)=(7,-3)\\\\2)\left \{ {{3x+2y=1} \atop {2x+5y=8}} \right. \\\\\left \{ {{x=\frac{1}{3}-\frac{2}{3}y } \atop {2x+5y=8}} \right. \\\\2(\frac{1}{3}-\frac{2}{3}y)+5y=8\\ \\y=2\\ \\x=\frac{1}{3}-\frac{2}{3}*2\\ \\x=-1\\ (x,y)=(-1,2)$