Well lets see. You have a total of 52 marbles. So all you would have to do would be to find the percent of 52 out of 60. This sounds confusing and I may not be completely right but I hope you give it a shot!
Answer: 
This is the same as writing 7*Ln( e^(2x) + 10) + C
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Explanation:
Start with the equation 
Apply the derivative and multiply both sides by 7 like so

The "multiply both sides by 7" operation was done to turn the 2e^(2x) into 14e^(2x)
This way we can do the following substitutions:

Integrating leads to

Be sure to replace 'u' with e^(2x)+10 since it's likely your teacher wants a function in terms of x. Also, do not forget to have the plus C at the end. This is a common mistake many students forget to do.
To verify the answer, you can apply the derivative to it and you should get back to the original integrand of 
Company A
Income = 35,000 + 0.03x
Company B
Income = 25,000 + 0.05x
set them equal to see how much of sales Julia needs to make the same income at both companies.
30,000 + 0.03x = 25,000 + 0.05x
30,000 - 25,000 = 0.05x - 0.03x
5,000 = 0.02x
5,000/0.02 = x
250,000 = x
Company A has better base salary and so would pay better if less than 250,000 sales are made. Company B has bigger percent bonus and would be a better deal if more than 250,000 sales are made.
So it's the 2nd choice.
14660 733-10x2 just add it all together and simplify