What is the equation of the line that passes through the point (-5,-3) and has a slope of -1?

Acable car begins its trip by moving up a hill. as it moves up, it gains elevation at a constant rate of 50 feet/minute until it reaches the peak at 2,000 feet. then, as the car moves down to the hill’s base, its elevation drops at the same rate.

Whats the name of the vertical axis

Can someone me and plz do the problem