Please help me with this I don't understand

Solve - pv + 40 < 65 for v solve 7w - 3r = 15 for r

Alake near the arctic circle is covered by a 222-meter-thick sheet of ice during the cold winter months. when spring arrives, the warm air gradually melts the ice, causing its thickness to decrease at a constant rate. after 333 weeks, the sheet is only 1.251.251, point, 25 meters thick. let s(t)s(t)s, left parenthesis, t, right parenthesis denote the ice sheet's thickness sss (measured in meters) as a function of time ttt (measured in weeks).

Build is 120 wide 20 feet high 48 feet long how many cubic feet and the volume