A: To find the rate in feet per minute, we can use the information given.
Every two minutes, the submarine dives 300 feet. So

.
In order to confirm that our rate is correct, we can use the second set of information given.

=

.
Since we know that the rate is 150 feet per minute, we can multiply it by any number of minutes and get the answer of how deep the submarine is. We can use a variable x to represent the number of minutes and y to represent the depth in feet.

There's our equation.
B: It would be more reasonable to use an equation with the rate feet per minute because it is more accurate since the time interval isn't too big.
8x - 13 = x + 1
Solve for x
Add 13
8x = x + 14
Subtract x
7x = 14, x = 2
Answer: the number is 2
20/100 x 8000 = 1600
1600 x 3 = 4800
8000 - 4800 = 3200
The motorcycle is worth $3,200 after three years.
The slope of the line is 
First, you must find 2 points.
(-6,8) (-2,5)
Then, you must substitute the value of the points in.

Finally, simplify the fraction.

Answer:
-7.2
Step-by-step explanation:
-4(0.3)-6
-1.2-6
-7.2