Question

Решите методом новых переменных
x3+y3=7
x3y3=-8 ​

Answer 1

X^3=а
Y^3=b
=> {a+b=7
a*b= -8
Тео.Виет
=> a=8
b=-1
=>x^3=7- y^3
X^3=7-(-1)
X= 2
Y^3= 7-x^3
Y^3 = 7-8
Y^3 = -1
Y= -1
Otv: x=2 y= -1 (2;-1)