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

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