SOLUTION: Differentiate with respect to x : y=3-2x/(1+x)^2. Simplifying your answer.

I would use u-substitution (first easy method I see, may be other ways):



   Let u = 1+x  ==>  du/dx = 1  

       x = u-1 ==>  2x = 2u-2



    dy/dx = (dy/du)(du/dx) 



Writing y in terms of u:

 



  



Since du/dx = 1, we just need to re-write the above in terms of x, so substitute back 1+x for u:



   



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