Question

Прошу помогите мне !​

Answer 1

Ответ:(1;1) (-1;1);(1;-1)(-1;-1)

Решение:

$\left \{ {{x^2+4y^2=5} \atop {x^2-8y^2=-7}} \right.\left \{ {{x^2+4y^2=5} \atop {x^2-x^2+4y^2-(-8y^2)=5-(-7})} \right. \left \{ {{x^2+4y^2=5} \atop {12y^2=12}} \right. \left \{ {{x^2+4y^2=5} \atop {y^2=12:12}} \right. \left \{ {{x^2+4y^2=5} \atop {y^2=1}} \right.$

$\left \{ {{x^2=5-4} \atop {y_{1} =-1}} \right. \left \{ {{x_{1} =-1;x_{2}=1 \atop {y_{1} =-1}} \right.$

$\left \{ {{x_{3}=-1;x_{4}=1 } \atop {y_{2}=1 }} \right.$