A pool is in the shape of a rectangular prism. On Monday, water was pumped out of the pool at a constant rate, starting at 12:00 p. m. At 12:15 p. m., the water in the pool was 45 inches deep. At 12:35 p. m., the water in the pool was 41 inches deep.

Part A
By how many inches does the depth of the water decrease each minute?

Enter your answer in the box.

? inch (es)

Part B
Write an equation that represents y, the depth of the water (in inches), after x minutes.

Enter your equation in the space provided. Enter only your equation.