Answer:
r=2
Step-by-step explanation:
r + 11 + 8r = 29
add the like terms
r+8r+11=29
9r+11=29
then subtract 11 on both sides to eltimate 11
9r=18
lastly divide 9 on both sides
r=2
Answer:
n=-15
Step-by-step explanation:
5=n/5+8
subtract 8 on both sides
-3=n/5
multiply 5 on both sides
-15=n
Let x be the number of times they raise the price on the newspaper. Then the new cost of the newspaper is

Let y be the newspaper they sell, then the income will be

Now, we know that the circulation is of 500, assuming that they sold every newspaper at the original price now the number the will sell will be

Plugging the value of y in the first expression we have that the income will be

Then the income is given by the function

To find the maximum value of this functions (thus the maximum income) we need to take the derivative of the function,

no we equate the derivative to zero and solve for x.

This means that we have an extreme value of the function when x=9. Now we need to find out if this value is a maximum or a minimum. To do this we need to take the second derivative of the function, then

Since the second derivative is negative in the point x=9, we conclude that this value is a maximum of the function.
With this we conclude that the number of times that they should raise the price to maximize the income is 9. This means that they will raise the price of the newspaper (9)($0.05)=$0.45.
Therefore the price to maximize the income is $0.35+$0.45=$0.80.
(a) Answer: One solution.
Explanation: two lines that have same slope with opposite sign will necessarily cross each other at a single point, as one is "pointing uphill" and the other "downhill."
(b) Answer: Infinitely many solutions.
Explanation:
2x + 3y = 5.5
4x + 6y = 11 | divide by 2
-->
2x + 3y = 5.5
2x + 3y = 5.5
--> equations are identical.
2x + 3y = 2x + 3y
so any (x,y) will satisfy this equation. This means infinitely many solutions.
(c) Answer: One solution
Explanation:
Continuing the two lines it becomes obvious they will cross at one point (the solution)
(d) Answer: No solution
Explanation: If the two lines are parallel, they will never cross (by definition of "parallel"). Therefore there will be no solution to the corresponding linear system.
Answer:
89*5
Step-by-step explanation: