Respuesta :
a good math calculator is called math-way it shows step by step answers. I hope this helps
[tex]\bf \cfrac{4x}{x^2-3x-18}-\cfrac{2x}{x^2+6x+9}\qquad
\begin{array}{lcclll}
x^2&-3x&-18\\
&\uparrow&\uparrow \\
& -6+3&-6\cdot 3\\\\
--&--&--\\\\
x^2&+6x&+9\\
&\uparrow &\uparrow \\
&3+3&3\cdot 3
\end{array}\\\\
-----------------------------\\\\
\cfrac{4x}{(x-6)(x+3)}-\cfrac{2x}{(x+3)(x+3)}\qquad LCD\to (x-6)(x+3)(x+3)
\\\\\\
\cfrac{4x(x+3)-2x(x-6)}{(x-6)(x+3)(x+3)}\implies \cfrac{4x^2+12x-2x^2+12x}{(x-6)(x+3)(x+3)}
\\\\\\
\cfrac{2x^2+24x}{(x-6)(x+3)(x+3)}\implies \cfrac{2x(x+12)}{(x-6)(x+3)(x+3)}[/tex]