http://prntscr.com/mvplq9
is the answer 2x/x+5
\(\quad\left(\dfrac{f}{g}\right)(x)\\ =\dfrac{4x^2+6x}{2x^2+13x+15}\\ =\dfrac{2x(2x + 3)}{(2x + 3)(x + 5)}\\ =\dfrac{2x}{x+5}\)
