Answer
$\infty$
Work Step by Step
$\int ^{\infty }_{a}f\left( x\right) dx=\lim _{N\rightarrow \infty }F\left( N\right) -F\left( a\right) \Rightarrow $
$\int ^{\infty }_{5}\left( 5\left( 0.36x\right) +5\right) dx=\lim _{x\rightarrow \infty }\left( 5x+\dfrac {5}{\ln 0.36}\times 0.36^{x}\right) -(5\times5+\dfrac {5}{\ln 0.36}\times 0.36^{5})=\infty $