There are 1 questions in this calculation: for each question, the 1 derivative of t is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ \frac{(a - c - ft)}{(b + e)}\ with\ respect\ to\ t：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = \frac{a}{(b + e)} - \frac{c}{(b + e)} - \frac{ft}{(b + e)}\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( \frac{a}{(b + e)} - \frac{c}{(b + e)} - \frac{ft}{(b + e)}\right)}{dt}\\=&(\frac{-(0 + 0)}{(b + e)^{2}})a + 0 - (\frac{-(0 + 0)}{(b + e)^{2}})c + 0 - (\frac{-(0 + 0)}{(b + e)^{2}})ft - \frac{f}{(b + e)}\\=& - \frac{f}{(b + e)}\\ \end{split}\end{equation} \]

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