Question

A research ship lowers a probe into the ocean to explore an underwater trench. The probe starts on a crane 16 feet above the surface and is lowered at a rate of 9.2 feet per minute. Write an expression for the depth of the probe after m minutes. What is the depth of the probe after 30 ​minutes?

Answer 1

9.2 is rate depth increases per minute.  This is same as slope (change in depth over change in time).

The surface of ocean is equal to depth of 0. Initial depth = -16 because it starts 16 ft ABOVE ocean. This is also when m = 0, similar to the "y-intercept"

Now we can write our function:
$D = 9.2m -16$