Show that x + 1 an d 2x - 3 are factors of 2x3 - 9x2 + x + 12.
To prove that (x + 1) and (2x - 3) are factors of 2x3 - 9x2 + x + 12 it is sufficient to show that p(-1) and p(3/2) both are equal to zero.
Hence, (x + 1) and (2x - 3) are the factors 2x3 - 9x2 + x + 12.