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

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