How do you solve this problem?

Jim is painting the inside of a circular helicopter pad. how many cans of paint would he need if the pad is 50 feet across and each can of paint covers about 200 ft2.

Average acceleration: i have no idea how to do this.

John used linear combination to solve the system of equations shown. he did so by multiplying the first equation by -3 and the second equation by another number to eliminate the x-terms. what number did jonas multiply the second equation by? 4x-6y=23x+5y=11