Question

решите уравнение:
2x(x+1)=x^2-1 

Answer 1

2x(x+1)=x^2-1 

2x^2+2x=x^2-1

2x^2-x^2+2x+1=0

2+2x+1=0

2x=-2-1

2x=-3

x=-3/2

Answer 2

2х^2 + 2x = x^2 - 1
2x^2 - x^2 +2x + 1 = 0
x^2 +2x + 1 = 0
D = 4-4 = 0
x= -2/2 = -1
Ответ:-1