30. suppose that the temperature at any point of a steel plate is given by (4,3), t 500-0.6x-1.5y, where x and y are measured in meters. at the point find the rate of change of temperature with respect to the distance traveled through the plate in the direction of x round to the nearest tenth. ) 12.2 â° / m b) 6.4 â° / m c) -4.8 â° / m d) 4.4 â° / m e) 44.2 â° / m