How to find derivative of function y=(3x-e^x)/(3x+e^x)?

We'll just have to apply the quotient rule to find out the
derivative of the given function:

(f/g)' = (f'*g -
f*g')/

Let f(x) = 3x - => f'(x) = 3 -

Let g(x) = 3x + => g'(x) = 3 +

dy/dx = [(3- )(3x+)- (3x-
)(3+ )]/

dy/dx = (9x + 3 -
3x- - 9x-3x+ 3 +  )/

We'll combine and eliminate like
terms:

dy/dx = (6 - 6x
)/

dy/dx = 6 (1 -
x)/

The requested derivative
of the function is dy/dx = 6 (1-x)/
.