Question

Решите систему уравнений X^2y+xy^2=126 x+y=9

Answer 1

$x^{2} y+x y^{2} =126 \ xy*(x+y)=126 \ xy*9=126 \ xy=14 \ \ x+y=9; x=9-y \ (9-y)*y=14 \ y^{2}-9y+14=0 \ D=81-4*14=25 \ y_{1}= frac{9+5}{2}= 7; y_{2} = frac{9-5}{2}=2$
Ответ: (7;2) (2;7)