Answer:
First, you have to factorize the expressions :
[tex] \frac{5x + 20}{8 {x}^{5} } \times \frac{x}{ {x}^{2} - 16} [/tex]
[tex] = \frac{5(x + 4)}{8 {x}^{5} } \times \frac{x}{(x + 4)(x - 4)} [/tex]
Second, you have to cross out the similar expressions :
[tex] = \frac{5}{8 {x}^{5} } \times \frac{x}{(x - 4)} [/tex]
Third, you have to multiply both fractions :
[tex] = \frac{5x}{8 {x}^{5}(x - 4) } [/tex]
Lastly, you have to simplify :
[tex] = \frac{5}{8 {x}^{4}(x - 4) } [/tex]