Find all roots of the polynomial $2x^3-3x^2-23x+30$ using the Rational Root Test (RRT).

Step 1 ：Step 1: Use the Rational Root Test (RRT) to list all possible rational roots. According to the RRT, if a polynomial has a rational root $p/q$, where $p$ and $q$ are integers with $q\ne 0$, then $p$ is a factor of the constant term (30) and $q$ is a factor of the leading coefficient (2). So, the possible rational roots are: $\pm 1,\pm 2,\pm 3,\pm 5,\pm 6,\pm 10,\pm 15,\pm 30,\pm 1/2,\pm 3/2,\pm 5/2,\pm 15/2$.

Step 2 ：Step 2: Use synthetic division or the Remainder Theorem to test each possible root. We find that $x=2,-3/2,5$ are roots of the polynomial.

Step 3 ：Step 3: Verify the roots by substituting them back into the original polynomial. It is found that they satisfy the polynomial equation.