There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ 40x + \frac{600x}{(x + 15)}\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = 40x + \frac{600x}{(x + 15)}\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( 40x + \frac{600x}{(x + 15)}\right)}{dx}\\=&40 + 600(\frac{-(1 + 0)}{(x + 15)^{2}})x + \frac{600}{(x + 15)}\\=& - \frac{600x}{(x + 15)^{2}} + \frac{600}{(x + 15)} + 40\\ \end{split}\end{equation} \]

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