Pls help its timed no fake answers i cant afford to fail

Based on what i know about mean, this doesn't add up.

Each of the four sides of a swimming pool measures 9 meters. the pool is 5 meters deep. how much water will be needed to fill it completely? a. 45 cubic meters b. 81 cubic meters c. 225 cubic meters d. 405 cubic meters reset next

Determine if the solution set for the system of equations shown is the empty set, contains one point or is infinite. x + y = 5 x + y = 7 {} 1 solution infinite