A Winter Storm Front Moves Through Campus $T ( t ) = 35 - 2 t ^ { 2 } + t$

Short Answer

A winter storm front moves through campus. At t hours after the onset of the storm, the temperature is given by $T ( t ) = 35 - 2 t ^ { 2 } + t$ . At what instantaneous rate is the water flowing when t = 4?
Enter your answer as just a real number to one decimal place, no units.