Please help! is about Quadratic functions

Find the arc length of the semicircle. 7the grade

More than 450450 students traveled to a state park for a field trip. the school allowed 66 students to travel by car, and the rest traveled on 1111 buses, each of which held the same number of students. if there were ss students in each bus, which inequality best represents this situation?

Me with these questions , i don’t understand scientific notation!