A rock is dropped from the top of a 500-foot cliff. After 1 second, the rock is traveling 45 feet per second. After 3 seconds, the rock is traveling 109 feet pem second. Let y be the rate of descent and x be the number of seconds since the rock was dropped.

a. Write a linear equation that relates time x to rate y. Hint: Use the ordered pairs (1,45) and (3,109)
b. Use this equation to determine the rate of travel of the rock 5 seconds after it was dropped,

The linear equation that relates time x to rate y is y=___