\(\displaystyle w = xe^{\frac{y}{z}} \)

\(\displaystyle x = t^4 \)

\(\displaystyle y = 6 - t \)

\(\displaystyle z = 1 + 5t \)

\(\displaystyle \frac{dw}{dt} = e^{\frac{y}{z}}(4t^3) + xe^{\frac{y}{z}}(\frac{1}{z})(-1) + xe^{\frac{y}{z}}(\frac{-y}{z^2})(5) \)

\(\displaystyle \frac{dw}{dt} = e^{\frac{y}{z}}(4t^3-\frac{x}{z}-\frac{5xy}{z^2}) \)

(Headbang)

If anyone can explain what I have done wrong, I'd be extremely thankful