Answer: r=(-189)
first you subtract both sides by 8 and get -21=r/9
then you multiply 9 with each side and get -189 = r
you can check by rewriting the problem with -189 as r and solving the equation
A) T(m) = -0.16m +331.3
B) T(2015) = 8.9 . . . seconds
_____
The linear regression function of a graphing calculator can find the equation of the line easily. Or, you can use the 2-point form of the equation of a line.
.. T(m) = (10.5 -14.5)/(2005 -1980)*(m -1980) +14.5
.. T(m) = -0.16(m -1980) +14.5
Median mean to find the center of the data
To answer this question we can propose the following equation:

Where:
x is the number of weeks elapsed.
d is the debt depending on the weeks.
Robert promised to pay at least $ 67 each week.
Therefore, after 5 weeks the debt of rober should be:


Then scenario A) is possible because
.
After 6 weeks:


Then scenario B) is possible because
.
After 7 weeks


Then scenario C) is possible because
.
After 8 weeks


So scenario D) is NOT possible because 
Finally the correct answer is option D.
Answer:
27
Step-by-step explanation:
x + y = 30
0.05x + 0.15y = 1.80
x = 30 - y
1.5 - 0.05y + 0.15y = 1.80
0.10y = 0.30
y = 3 (bottles)
x = 27 (cans)