If the sides of the rectangle are a and b,
Area=ab=3200^2
If the side with a ft cost $2/ft and side with bft costs $2/ft
Then,
Cost = 2*2*a+2*1*b=4a+2b
At minimum cost (or critical point), the derivative of cost =0
From area, b=3200/a
Using cost equation
C=4a+2*3200/a=4a+6400/a
First derivative with respect to a;
C'(a)=4-6400/a^2=0
Then, a=+/-40 The negative value is rejected. Therefore, a=40 ft and b=3200/40= 80 ft.
Therefore, a=40 ft and b=80 ft to minimize the fencing cost.
The answer would be $17.32. The tip would be $2.14. And the sales tax would be $0.93.
If you add them altogether you get $17.32
31 because two more tens is equal to 20. so 20+11 is 31
I believe the correct answer is 6.3