Question

Решите систему уравнений
{x=y²-4y
{x+y=4

Answer 1

$\displaystyle\left \{ {{x=y^{2}-4y } \atop {x+y=4}} \right. \\\\\\\displaystyle\left \{ {{x=4-y} \atop {4-y=y^{2} -4y}} \right. \\\\\\\displaystyle\left \{ {{x=4-y} \atop {y^{2}-3y-4=0 }} \right. \\\\\\\displaystyle\left \{ {{x=4-y} \atop {\left[\begin{array}{ccc}y_{1} =4\\y_{2} =-1\end{array}\right} \right. \\\\\\\left[\begin{array}{ccc}\left \{ {{x_{1} =0} \atop {y_{1} =4}} \right. \\\left \{ {{x_{2} =5} \atop {y_{2} =-1}} \right. \end{array}\right$

$Otvet:\boxed{(0 \ ; \ 4) \ , \ (5 \ ; -1)}$