Okay. so let's get the limits out of the way.
we already saw that the new limits for u are and . so good.
Now,
.............(by the chain rule)
..........................multiplied both sides by 5
What Luck! the right hand side is exactly our integral. this does not always happen, but it is really nice here, and we won't complain. so we can simply replace our entire integral with 10/3 in du.
So, our integral becomes:
and then just plug that into your calculator
do you get it?