Step 1 :Separate the integral into two parts: \(\int_{1}^{8}\frac{6}{x} dx\) and \(\int_{1}^{8}-e^{-x} dx\).
Step 2 :Calculate the integral of each part separately. The integral of \(\frac{6}{x}\) is \(6*ln|x|\) and the integral of \(-e^{-x}\) is \(e^{-x}\).
Step 3 :Evaluate these at the limits of 1 and 8.
Step 4 :The integral of \(\frac{6}{x}\) from 1 to 8 is \(6*ln|8| - 6*ln|1| = 12.476649250079014\).
Step 5 :The integral of \(-e^{-x}\) from 1 to 8 is \(-e^{-8} + e^{-1} = 0.3675439785435398\).
Step 6 :Add these two results together to get the final result: \(12.476649250079014 + 0.3675439785435398 = 12.844193228622553\).
Step 7 :Final Answer: The value of the integral is \(\boxed{12.844193228622553}\).