Rewrite the equation as,
$$\frac{\left( \frac35 x-\frac45 y-\frac15\right)^2}{4}-\frac{\left( \frac45 x+\frac35 y-\frac15\right)^2}{9}=1$$
which is the regular hyperbola
$$\frac{\left( x-\frac15\right)^2}{4}-\frac{\left( y-\frac15\right)^2}{9}=1$$
with the rotation of $\theta=\cos^{-1}\frac35$. Therefore,
$$a=2, \>\>\>\>\>b=3$$
which allows the latus rectum $2b^2/a$ to be calculated.