7:20 sorry if not right in a rush
also will ask that you rate this and not just take the answer
I would recommend "Introduction to Linear Algebra," by Gilbert Strang. It is a compact but very helpful textbook reference written by a well-known MIT professor. There is a corresponding online MIT course that is free, so that's a bonus. I am currently using it to study linear algebra with no class or previous experience, and I think it does a solid job of explaining things. Each section in the book has a set of questions for you to work through, and answers to selected questions appear in an appendix at the end of the book.
Hope this helps!
It should be 18, because despite of 3,14, because that's pi and radius is half of the diameter, so36 divide 2 is 18.
There would be 107 whistles
-equation- 235-128=107
