There are 1 questions in this calculation: for each question, the 1 derivative of t is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ -3A{e}^{(-3t)} - 3Bt{e}^{(-3t)} + B{e}^{(-3t)}\ with\ respect\ to\ t：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( -3A{e}^{(-3t)} - 3Bt{e}^{(-3t)} + B{e}^{(-3t)}\right)}{dt}\\=&-3A({e}^{(-3t)}((-3)ln(e) + \frac{(-3t)(0)}{(e)})) - 3B{e}^{(-3t)} - 3Bt({e}^{(-3t)}((-3)ln(e) + \frac{(-3t)(0)}{(e)})) + B({e}^{(-3t)}((-3)ln(e) + \frac{(-3t)(0)}{(e)}))\\=&9A{e}^{(-3t)} - 6B{e}^{(-3t)} + 9Bt{e}^{(-3t)}\\ \end{split}\end{equation} \]

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