Question

Решите способом подстановки систему уравнений

Answer 1

$1)\left \{ {{xy+x=-4} \atop {x-y=6}} \right.\\\\\left \{ {{y=x-6} \atop {x*(x-6)+x=-4}} \right.\\\\\left \{ {{y=x-6} \atop {x^{2}-6x+x+4=0 }} \right. \\\\\left \{ {{y=x-6} \atop {x^{2}-5x+4=0 }} \right.\\\\\left \{ {{y=x-6} \atop {\left[\begin{array}{ccc}x=1\\x=4\end{array}\right }} \right.\\\\\left \{ {{\left[\begin{array}{ccc}x=1\\y=1-6=-5\end{array}\right } \atop {\left[\begin{array}{ccc}x=4\\y=4-6=-2\end{array}\right }} \right.\\\\Otvet:\boxed{(1;-5),(4;-2)}$

$2)\left \{ {{x+y=9} \atop {y^{2}+x=29}} \right.\\\\\left \{ {{x=9-y} \atop {y^{2}+9-y-29=0 }} \right.\\\\\left \{ {{x=9-y} \atop {y^{2}-y-20=0 }} \right. \\\\\left \{ {{\left[\begin{array}{ccc}y=-4\\x=9-(-4)=13\end{array}\right } \atop {\left[\begin{array}{ccc}y=5\\x=9-5=4\end{array}\right }} \right. \\\\Otvet:\boxed{(13;-4),(4,5)}$