You can
put this solution on YOUR website! .
I came to show you how to do it correctly:
You should apply first the rule of differentiating a product
(uv)' = u'*v + u*v'
and then apply the chain differentiating rule :
((2x+5)^2*(x-4)) = 2*(2x+5)*2*(x-4) + (2x+5)^2. ANSWER
I mean : the correct answer.