I NEEED HELP PLEASE

What is the missing constant term in the perfect square that starts with x^2 -20x

For a field trip to the zoo, 4 students rode in cars and the rest filled nine busess. how many students were in each bus if 472 students were on the trip

Which inequality is equivalent to -3x < -12? x < 4 , x < -4 , x > 4, x > -4