Find all rational zeros of the polynomial $$P(x)=x^4 + 1 x^3 - 10 x^2 + 2 x - 24$$
Its rational zeros are $x_1=$, $x_2=$, $x_3=$ and $x_4=$ with $x_1\le x_2\le x_3\le x_4$
If the polynomial has only three rational zeros, input them at $x_1$, $x_2$ and $x_3$; If the polynomial has only two rational zeros, input them at $x_1$ and $x_2$; if the polynomial has only one rational zero, input it at $x_1$.