Answer:
[tex]{ \rm{ \frac{6 {x}^{2} + 18x }{2 {x}^{3} } = \frac{5}{x} }} \\ \\ { \rm{ \frac{3x + 9}{ {x}^{2} } = \frac{5}{x} }} \\ \\ { \rm{x(3x + 9) = 5 {x}^{2} }} \\ { \rm{3 {x}^{2} + 9x = 5 {x}^{2} }} \\ { \rm{3x + 9 = 5x}} \\ { \rm{2x = 9}} \\ { \rm{x = 4.5}}[/tex]