[tex]f(x)=-\dfrac{x}{11}\to y=-\dfrac{x}{11}\\\\\text{exchange x to y}\\\\x=-\dfrac{y}{11}\\\\\text{solve for y}\\\\-\dfrac{y}{11}=x\qquad\text{multipsides by (-11)}\\\\\boxed{y=-11x}\\\\Answer:\ f^{-1}(x)=-11x[/tex]
