There are 1 questions in this calculation: for each question, the 1 derivative of K is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ 9K + L + Q(120 - (8{K}^{\frac{1}{2}}){L}^{\frac{1}{2}})\ with\ respect\ to\ K：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = 9K - 8L^{\frac{1}{2}}QK^{\frac{1}{2}} + 120Q + L\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( 9K - 8L^{\frac{1}{2}}QK^{\frac{1}{2}} + 120Q + L\right)}{dK}\\=&9 - \frac{8L^{\frac{1}{2}}Q*\frac{1}{2}}{K^{\frac{1}{2}}} + 0 + 0\\=& - \frac{4L^{\frac{1}{2}}Q}{K^{\frac{1}{2}}} + 9\\ \end{split}\end{equation} \]

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