We have to find the zeros of the polynomial f(x) = 2x^3-23x^2-28x-8.
The independent coefficient is -8, that has factors ±1,±2,±4 and ±8.
The leading coefficient is 2, and has factors ±1 and ±2.
The possible rational zeros (p/q) are: ±1/2, ±2/2=±1, ±4/2=±2 and ±8/2=±4.
The possible rational zeros are: ±1/2, ±1, ±2 and ±4.