A. You may set the variables in either order. But for argument sake, let's set as follows:
x = Amount of bookshelves
y = Amount of tables
B. Because of the amount of things you need to make, the following is an inequality using those variables.
x + y > 25
Plus you can determine a second inequality based on the amount of money that you have to spend.
20x + 45y < 675
Finally you may also add in that each value must be greater than or equal to zero, since they cannot have negative tables.
C. By solving the system and looking at basic constraints when graphed, you can see the feasible region has 4 vertices.
(0,0)
(18, 7)
(0, 15)
(33.75, 0) or (33, 0) if you insist on rounding.
Yes the proportial relationship all increase by the same number so that would be your rate of change
Repari cost (x) = y = 35.25 x + 40
x = number of hours to repair the car.
Every hour the cost will increase 35.25, becasue 40 is a fixed cost.
if x = 1, repair cost(1) = 35.25 + 40
if x = 2, repair cost (2) = 35.25*2 + 40
if you subtract repair cost (1) from repair cost (2) you get 35.25*2 - 35.25 = 35.25
The same thing every time the repair time increases one hour.
Answer: the last option of the list, for every hour of labor, the cost increases by $35.25
Parenthesis according to the PEMDAS rule
So
7(x - 4) = 84
Would be
7x -28 = 84
Hope this helped :)
