When do you use u substitution in integration

Ineeeeed this is due tomorrow and i dont know the answer can you find all the exponents

How many kilometers are equal to 5 miles? use 1 mile ≈ 1.61 kilometers. !

Using pert, adam munson was able to determine that the expected project completion time for the construction of a pleasure yacht is 21 months, and the project variance is 4. a) what is the probability that the project will be completed in 17 months? b) what is the probability that the project will be completed in 20 months? c) what is the probability that the project will be completed in 23 months? d) what is the probability that the project will be completed in 25 months? e) what is the due date that yields a 95% chance of completion?