Respostas

2014-03-10T07:56:21-03:00
(x+1)(x²-x+1) = ( x.x^2 - x. x + x.1) + (1 . x^2 - 1. x + 1.1)
                     = x^3 - x^2 + x + x^2 - x + 1
                     =  x^3 + 1
2014-03-10T08:26:49-03:00
(x+1)(x²-x+1) aplica a propriedade distributiva
x(x²-x+1)+1.(x²-x+1)
x³-x²+x+x²-x+1
x³-x²+x²-x-x+1
x³+1
x³=-1
x=∛(-1) =>x=-1