6x + 7(1-x) = -4(x-4)
6x + 7 - 7x = -4x + 16
-x + 7 = -4x + 16
-x + 4x = 16 - 7
3x = 9
x =9/3
x = 3
The question is incomplete. Here is the complete question.
As a part of city building refurbishment project, architects have constructed a scale model of several city builidings to present to the city commission for approval. The scale of the model is 1 inch = 9 feet.
The model includes a new park in the center of the city. If the dimensions of the park in the model are 9 inches by 17 inches, what are the actual dimensions of the park?
Answer: 81 feet by 153 feet
Step-by-step explanation: <u>Unit</u> <u>Scale</u> is a ratio comparing actual dimensions of an object to the dimensions of model representing the actual object.
In the refurbishment project, the unit scale is given by
1 inch = 9 feet
So, the dimensions of the new park in actual dimensions would be
1 inch = 9 feet
9 inches = x
x = 9.9
x = 81 feet
1 inch = 9 feet
17 inches = y
y = 17.9
y = 153 feet
The actual dimensions of the new park are 81 feet by 153 feet.
Q(p) = k/p^3 . . . . . . . . we want to find k
q(10) = k/10^3 = 64
k = 64,000
Revenue = q(p)*p = 64000/p^2
Cost = 150 +2q = 150 +2*64000/p^3
Profit = Revenue -Cost = 64000/p^2(1 -2/p) -150
Differentiating to find the maximum profit, we have
.. dProfit/dp = -2(64000/p^3) +6(64000/p^4) = 0
.. -1 +3/p = 0
.. p = 3
A price of $3 per unit will yield a maximum profit.