I really need help with a math question involving differentiating a function

Q: Differentiate f(x) = (1 + xe^x) / (x - e^x)

Can someone please explain how to solve this question?

if f = u / v
then f´= (v u´ - u v´)/ v^2

f = (1 + xe^x) / (x - e^x)

u = (1 + xe^x)
u´= 0 + e^x + xe^x

v = (x - e^x)
v´= 1 - e^x

so, f´(x) = [ (x - e^x)(e^x + xe^x) - (1 + xe^x) (1 - e^x) ] / (x - e^x)^2

then try to simplify it. Good luck