Step 1 :Given the first order ordinary differential equation \(\frac{d x}{d t} = \frac{5 \sqrt{t^{3}}-7 t}{\sqrt{t^{3}}}, \quad x(9)=8\)
Step 2 :Integrate the right hand side of the equation with respect to t to find the antiderivative.
Step 3 :The antiderivative is \(-14t^{2/\sqrt{3}} + 5t\)
Step 4 :Use the initial condition x(9)=8 to find the constant of integration.
Step 5 :The constant of integration is 5.
Step 6 :Substitute the constant of integration into the antiderivative to find the particular solution.
Step 7 :The particular solution is \(x(t) = -14t^{2/\sqrt{3}} + 5t + 5\)
Step 8 :\(\boxed{x(t) = -14t^{2/\sqrt{3}} + 5t + 5}\) is the final answer.