There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ (0.25x + 25)(-2x + 100) - 20(-2x + 100)\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = -0.5x^{2} + 25x - 50x + 40x + 500\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( -0.5x^{2} + 25x - 50x + 40x + 500\right)}{dx}\\=&-0.5*2x + 25 - 50 + 40 + 0\\=&-x + 15\\ \end{split}\end{equation} \]

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