Answer
The answer is $y=(11/7)x+311/63$.
Work Step by Step
Using Eq. (8) the slope of the tangent line is given by
$\frac{dy}{dx}=\frac{y'(t)}{x'(t)}=\frac{-27 t^2-30 t+24}{-9 t^2+6 t+6}$.
So,
$\frac{dy}{dx}|_{t=1/3 }=\frac{11}{7}$.
At $t=1/3$, $c(1/3)=(29/9,10)$. Thus, the equation of the tangent line at $t=1/3$ is
$y-10=(11/7)(x-29/9)$
So,
$y=(11/7)x+311/63$.