And from that it should be easy to see that dx= (1/3)du.
I have no idea what you could mean by "do i divide by 3 to produce 1?". Divide what by 3? "Produce 1" where and how? The more precise you are in mathematics, the bettter. Practise being precise.After this step i dont know what to do , do i divide by 3 to produce 1?
Please answer in step .Thank you