Volume of cones maze

Which statement justifies why angle ebc measures 90?

The function f(x)= x5+ ( x + 3)2 is used to create a table. if x = -1 then what is f(x)?

Kim took out a $55,000 loan for college she is borrowing money from 2 banks bank a charges an interest rate of 8% and b charges an interest rate of 11% after one year kim owes 5000 in interest how much money did she borrow from bank a.