Linear Modeling
The equation y = -4x can be used to model the change in depth of the descent of the DeepSea Challenger, where y is the depth in feet and x is the time in seconds.
For example, for x=10 seconds, the vessel had traveled y= -4*10 = -40 feet.
The bottom of Challenger Deep in the Marianas Trench is 35,814 feet deep at its lowest point.
If we use the model, we can find the value of x when y= -35,814 feet
-35,814 =-4x
Dividing by 4:
x = -35,814/ (-4)
x = 8,953.5 seconds
The model suggests the DeepSea Challenger took almost 9,000 seconds to reach the bottom