اگر $f(x)=۲x+۳$ و $g(x)=x-۴$ مقدار $\frac{(fog)(۲)}{(gof)(-۱)}$ چقدر است؟
$\begin{align} & f(x)=2x+3,g(x)=x-4 \\ & (1)\,(fog)(2)=f(g(2)) \\ & g(2)=2-4=-2 \\ & f(g(2))=f(-2)=2(-2)+3=-4+3=-1 \\ & (2)(gof)(-1)=g(f(-1))=g(1)=1-4=-3 \\ & \Rightarrow \frac{(fog)(2)}{(gof)(-1)}=\frac{-1}{-3}=\frac{1}{3} \\ \end{align}$