P5—-Differential Calculus

Pls, I can remember my differential calculus very well. Can you please help me on how to solve a linear relationship with respect to the following question;

Total Cost= 5000+0.6x
Total revenue= 20x – 0.01x^2

1. Dertermine the level of output to maximise profit?
2. What should price be where TC=TR?
3. Explain the structure of this model?

Thanks for your help.