How to interprete output of solve function ?

Hello, I'm trying to solve with math tool box a non liner equation :

with the code

syms x
solve ( x^2-(1+x)^2 + x^2*(1+x)^2 )

The output I can't understand is :

 root(z^4 + 2*z^3 + z^2 - 2*z - 1, z, 1)
 root(z^4 + 2*z^3 + z^2 - 2*z - 1, z, 2)
 root(z^4 + 2*z^3 + z^2 - 2*z - 1, z, 3)
 root(z^4 + 2*z^3 + z^2 - 2*z - 1, z, 4)

How shoul I interpret this ? I would like somthing more like a numeric root but maybe the problem is with the equation itself?

Answer 1

[madhan ravi]

syms x
double(solve ( x^2-(1+x)^2 + x^2*(1+x)^2 , 'MaxDegree', 4))