There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ {e}^{(-(\frac{(x - 20)}{(\frac{4}{5}t)}))}\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = {e}^{(\frac{\frac{-5}{4}x}{t} + \frac{25}{t})}\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( {e}^{(\frac{\frac{-5}{4}x}{t} + \frac{25}{t})}\right)}{dx}\\=&({e}^{(\frac{\frac{-5}{4}x}{t} + \frac{25}{t})}((\frac{\frac{-5}{4}}{t} + 0)ln(e) + \frac{(\frac{\frac{-5}{4}x}{t} + \frac{25}{t})(0)}{(e)}))\\=&\frac{-5{e}^{(\frac{\frac{-5}{4}x}{t} + \frac{25}{t})}}{4t}\\ \end{split}\end{equation} \]

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