Respuesta :

Answer:

[tex] \frac{1}{ {u}^{28} } [/tex]

solution,

[tex] {(u}^{4} \: )^{ - 7} \\ = {(u)}^{4 \times ( - 7)} \\ = {(u)}^{ - 28} \\ = \frac{1}{ {u}^{28} } [/tex]

Hope this helps...

Good luck on your assignment..