Here's the quadratic I need to solve: $\displaystyle 2x^2 -7x > 4$

Now I know the solutions are $\displaystyle 4, -\frac {1}{2}$ but my book shows a number line that essentially has $\displaystyle x > 4$ and $\displaystyle x < -\frac {1}{2}$ Why is this the case? Why aren't they all "greater than" inequalities?