Hello, I can't seem to solve these questions please help.

4. [0/1 Points] DETAILS PREVIOUS ANSWERS BERRAPCALC7 5.6.019.MI. MY NOTES PRACTICE ANOTHER Find the indefinite integral by the substitution method or state that it cannot be found by our substitution formulas. (If it cannot be found by substitution, enter IMPOSSIBLE. Use C for the constant of integration.) x8 dx - (9 ) (8 ) 60 /00 H + C Co / 00 X Need Help? Read It Master It7. [0/1 Points] DETAILS PREVIOUS ANSWERS BERRAPCALC7 5.6.071. MY NOTES PRACTICE ANOTHER An experimental drug lowers a patient's blood serum cholesterol at the rate of ty 100 - t2 units per day, where t is the number of days since the drug was administered (0 s t s 10). Find the total change during the first 6 days. X units Need Help? Read It Submit Answer 8. [0/1 Points] DETAILS PREVIOUS ANSWERS BERRAPCALC7 5.6.075. MY NOTES PRACTICE ANOTHER A factory is discharging pollution into a lake at the rate of r(t) tons per year given below, where t is the number of years that the factory has been in operation. Find the total amount of pollution discharged during the first 5 years of operation. (Round your answer to two decimal places.) r(t) = - 12 + 1 X tons Need Help? Read It Submit