After multiplying by x, the equation becomes x^4 + x -2 + 0
There are 2 real roots as you can see by the graph & the other 2 roots are complex.
You can see that 1 is a root by inspection and by using the Newton method, you get a second root of -1.353210
You cannot get the other 2 roots using Newtons method. So when you divide by x+1.353210, you end up with the quadratic equation x^2 -.35321x + 1.4779673
Use the quadratic equation to obtain the other 2 roots .176605 +- 1.20282i