I am having a hard time trying to get the answers to a few problems. I was hoping that someone could help me?

u/11=8/13 solve for u. I came up with the answer of u=6.67923

-15/z-1=18/z

and

2w/3z times 7z/4wz I got the answer 7*z/6 but I do no think that is correct.

and x+1/4x+8*x^2-x-6/x^2-1 the answer I got was (x-3)/4(x-1)

Can someone please help me??

Please use proper grouping symbols so we may know exactly what the expression or equation is. Especially for the last one.

The way it is written, with no parentheses, it can be taken as various things.

The way it is written is:

Hello crystal

u/11=8/13 --> The answer you provided is correct. Excellent !
So follow up the other questions in a similar fashion !