It looks like the given equation says
[tex]xy^8 + e^{y/5} = e[/tex]
When x = 0, you have
[tex]0\cdot y^8 + e^{y/5} = e \\\\ e^{y/5} = e^1 \\\\ \dfrac y5 = 1 \\\\ y=5[/tex]
Differentiating both sides with respect to x gives
[tex]\left(xy^8 + e^{y/5}\right)' = e' \\\\ \left(xy^8\right)' + \left(e^{y/5}\right)' = 0 \\\\ x\left(y^8\right)' + x'y^8 + e^{y/5}\left(\dfrac y5\right)' = 0 \\\\ 8xy^7y' + y^8 + \dfrac15e^{y/5}y' = 0[/tex]
That is, the derivative operator distributes over sums, and the derivative of a constant is 0; apply the product rule on the first term and chain rule on the second; then use chain rule one more time.
Now plug in x = 0 and y = 5, and solve for y' :
[tex]8\cdot0\cdot5^7y' + 5^8 + \dfrac15e^{5/5}y' = 0 \\\\ 5^8 + \dfrac15e y' = 0 \\\\ \dfrac15e y' = -5^8 \\\\ y' = \boxed{-\dfrac{5^9}e}[/tex]
