Question

Решить систему: x-y=-5 x^2-2xy-y^2=17

Answer 1

$\left \{ {{x-y=-5} \atop {x^2-2xy-y^2=17}} \right. \\ \left \{ {{x=y-5} \atop {x^2-2xy+y^2-2y^2=17}} \right. \\ \left \{ {{x=y-5} \atop {(x-y)^2-2y^2=17}} \right. \\ (y-5-y)^2-2y^2=17 \\ 25-17=2y^2 \\ y^2=8/2=4 \\ y=2; -2 \\ x=y-5=2-5=-3;-2-5=-7$
отв:(-3;2); (-7;-2)