Please help answer 4 & 7 all parts!! Thank you so much!

4. Use the substitution method to find the following indefinite integrals. a. S 6x73x3 - 1 dx b. J -z dx 7. Amazon's revenue was growing at the rate of R' (x) = 0.55e 0.4t on 0 St s5 billon dollars/year in year t with t=0 corresponding to 2010. The revenue of the company was 12.5 billion dollars in 2010. a. By how much did the revenue of Amazon increase over the period over the period from 2010 through 2015? b. What was the revenue of the company in 2015