Let P be a point on the parabola y² = 4ax, where a > 0 . The normal to the parabola at P meets the x -axis at a point Q. The area of the triangle PFQ , where F is the focus of the parabola, is 120. If the slope m of the normal and $a$ are both positive integers, then the pair  $\left(a,m\right)$ is