jika f(x)=2x+3/x+5 maka f^-1(3)=

[tex]$\begin{align}f(x)&=\frac{2x+3}{x+5}\\y&=\frac{2x+3}{x+5}\\y(x+5)&=2x+3\\xy+5y&=2x+3\\xy-2x&=3-5y\\x(y-2)&=3-5y\\x&=\frac{3-5y}{y-2}\\f^{-1}(x)&=\frac{3-5x}{x-2}\\f^{-1}(3)&=\frac{3-5(3)}{3-2}\\&=\frac{3-15}{1}\\&=\boxed{-12}\end[/tex]