Originally Posted by

**EternalChicken** Hey. Have a question for my work, and need a little help getting the answer. Have been looking up the chain rule for some previous questions, but am now stuck, as i have not had one like this before. I'm not gonna give the actual question, as i want to work that out myself, but here is how it is styled:

differentiate 5x(9-3x)

so, normally that would be ok, but i havent had one with an x n the outside of the brackets, and am not sure what to do with it. Do i turn it into 5? but then that wouldn't make sense with the chain rule, so do i leave 5x as it is...

Help much appreciated.

Many thanks