Question

Помогите решить системы:
1) {2x-y=6
{2x^2+y^2=66

2) {x+y=2
{2x^2-xy=65

Answer 1

$\left \{ {{2x-y=6 } \atop {2 x^{2} +y ^=66 }} \right. \left \{ {y=2x-6} \atop }} \right. 2x^2+(2x-6)^2=66 2x^2+4x^2-24x+36=66 6x^2-24x-30=0 D=576-4*6*(-30)=1296; \sqrt{1296=36} x_{1} =24-36/12=-1 x_{2} =24+36/12=5 y_{1} =2*(-1)-6=-8 y_{2} =2*5-6=4  Ответ:(-1;-8) (5;4)$