So lets start by getting rid of the fraction. In order to do this we must move the 'u' to the other side by multiplying it.
[tex]8*u = -\frac{4}{u}*u [/tex]
[tex]8u = -4[/tex]
Now we need to isolate the 'u' so we must bring the 8 over to the other side by dividing both sides by 8.
[tex]\frac{8u}{8} = \frac{-4}{8} [/tex]
[tex]u = \frac{-4}{8} [/tex]
Therefore:
[tex]u = - \frac{1}{2} = -0.5 [/tex]
Hope this helps!
