Question 101413
The first approach is to try to factor it.

You know you will have:  (2x   )(x    ) for the x terms.  And since the constant is negative, one of the factors will have a - and the other will have a +.

You know that 14 = 2 * 7, which are your only choices.

So the only choices are
(2x + 2)(x - 7)
(2x - 2)(x + 7)
(2x + 7)(x - 2)
(2x - 7)(x + 2)

You're looking to the -3x, which is:'

(2x - 7)(x + 2)

ALWAYS check!
(2x - 7)(x + 2) = 2x*x + 2x*2 - 7*x - 7*2 = 2x^2 + 4x - 7x - 14 = 2x^2 - 3x - 14.