2 - x - 2*x - 1
-x^2 - 2*x - 1
x + 1
2 -1 - x - 2*x
-1 - x^2 - 2*x
-1.0 - x^2 - 2.0*x
2 -(1 + x)
-(1 + x)^2
-1 + x*(-2 - x)