Answer:
a) T(r) = r.D(r)
b) 975 people per square mile.
Step-by-step explanation:
(a)
The units of D(r) are

when multiplying the density by the area we get the amount of people in that area, so

(b)
The average rate of change of T(r) over the interval [5,7] is

but D(7) = 350 and D(5) = 100, so

and the average rate of change of T(r) over the interval [5,7] is 975 people per square mile.
Forget the 1996 for the moment. Just count the number of years that go by.
30500*(1.02)^x= 32500 + 600x The easiest way to handle this is either to use a spreadsheet or graph if. I don't see an algebraic way of doing it. I'll try the graph first.
The red line is y = 32500 + 600x
Now let's try a spreadsheet.
I can't copy and past a spreadsheet's contents, but it shows that they are about equal when x = 17.
y = 32500 + 600x gives 42700 when x = 17
y = 30500*(1.02)^17 gives 42707 when x = 17 You cannot get much closer than that.
Answer:

Step-by-step explanation:
We are given that the lines passes trough the points (-9, -1) and (0,0).
(0,0) is the origin.
Slope is: 

The slope is one-ninth.
Since the lines passes at the origin, it's y-intercept is 'zero'. We do not write zeros in slope-intercept equations, to the equation of the line should be:

I guess it is 79 but you have to check because I am not sure
Answer:
33x^2 - 50x + 8
Step-by-step explanation:
Multiply the length times the width.
Length: 3x - 4
Width: 11x - 2
(3x - 4)(11x - 2)
33x^2 - 50x + 8