Question

a submarine begins at a Depth of -120 feet below sea level. It ascended at a rate of 13 feet per minute (M). write an expression that could be used to describe the situation.

Answer 1

Data:

Depth: dTime: x

You can use the general form of a lineal equation:

`y=mx+b`

where y in this case is d the depth of the submarine in function of the time x.

m is the slope, or the change of the depth with x time (the rate of ascended). As the submarine ascended 13 feet per minute, the m is 13

b is the initial depth (the depth when the time x is 0) The initial depth is -120feet then b= -120

You substitute in the general form the next data:

m=13

b=-120

y=d

Then, you get the next equation to describe the situation:
`d=13x-120`

The distance (d) in function of the time (x)