Question

Система нелинейных уравнений

Answer 1

$left { {{x+y=5} atop {x^3+y^3=35}} right. \ \ x=5-y \ (5-y)^3+y^3=35 \ 5^3-3*y*5^2+3*5*y^2-y^3+y^3=35 \ 125-75y+15y^2=35 \ 15y^2-75y+90=0 \ y^2-5y+6=0\ D=b^2-4ac=1 \ y_1_,_2= frac{-b^+_- sqrt{D} }{2a} \ y_1=2 \ y_2=3 \ \ x_1=5-2=3 \ x_2=5-3=2$