There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ (0.012*21000 + 311 + 865 + 865*1.5(1.871 - 0.01x))(1 + 0.02x + 0.5)\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = 5.04x + 6.22x + 17.3x + 48.55245x - 12.975x - 0.2595x^{2} - 6.4875x + 5783.43375\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( 5.04x + 6.22x + 17.3x + 48.55245x - 12.975x - 0.2595x^{2} - 6.4875x + 5783.43375\right)}{dx}\\=&5.04 + 6.22 + 17.3 + 48.55245 - 12.975 - 0.2595*2x - 6.4875 + 0\\=& - 0.519x + 57.64995\\ \end{split}\end{equation} \]

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