Gabriela forgot to charge her phone after using it at the amusement park, and she didn't have her charger with her. Her battery drained at a constant rate. The power level of the battery, y, after x minutes is y=−0.5x+72. What do the slope and y-intercept represent in this situation? Write 2 to 3 sentences explaining how the slope and y-intercept are related to the cell phone battery. Be sure to use clear math language in your explanation.