For the function $y=x^4 - 5 x^3 - 6 x^2$,
its $y$-intercept is $y =$
its $x$-intercepts are $x=$ .
Note: If there is more than one answer enter them separated by commas. If there are none, enter none .
When $x\to \infty$, $y \to$ $\infty$ (Input + or - for the answer)
When $x\to -\infty$, $y \to$ $\infty$ (Input + or - for the answer)