Davide M. answered 02/13/21
PhD in Mathematics, former UCLA Researcher: Math and Physics Tutor
Maybe you referred to partial derivative, since partial fractions is a method to integrate a function.
In any case, you start by massaging your equation in order to have the variable z on the left hand side of an equality and all the other terms on the right hand side.
In this case, you should get z= 9/(xy) + (1/2)*x4y7 - e6xy/(2xy).
We now can evaluate the partial derivative of z with respect to y which will be the sum of the derivatives of the above three terms.
First term: 9/(xy)
The derivative of this term with respect to y is given by -9/(xy2)
Second term: (1/2)*x4y7
The derivative of this term with respect to y is given by (7/2)x4y6
Third term: exy/(2xy)
The derivative of this term with respect to y needs to be evaluated with the Quotient Rule and is given by the ration where at the numerator you have 6xye6xy-e6xyand at the denominator you have 2xy2
Putting all these things together you get the final result
-9/(xy2)+e(7/2)x4y6 -(1/2xy2)*(6xye6xy-e6xy)
Best,
Davide