Minimum cost to enclose 3000 sq ft garden with shrubs and fencing

[mugzieee]

a landscape architect plans to enclose a 3000 square foot rectangular region in a botanical garden. She will use shrubs costing $25 per foot along three sides and fencing costing $10 per foot along the fourth side. Find the minimum total cost.

I started off this problem by finding the length of the sides:
L=3000/w
W=3000/L
Then i determined that the total cost would be the cost of the length + cost of the width.

I am totally lost on this problem...

 

[Tide]

Just break it down using the information you have:

$$Cost = 25(2L+W) + 10W$$

and

$$W = \frac {3000}{L}$$

Then minimize the cost in the usual way.

 

[mugzieee]

hey thanks for your help tide, u just allowed me to take a deeeeeep breath, whewwww. oh btw, how do u write with those mathematical fonts?

 

[Tide]

hey thanks for your help tide, u just allowed me to take a deeeeeep breath, whewwww. oh btw, how do u write with those mathematical fonts?

If you click on one of the equations a popup will show how that specific equation was created but it also has a link to a file you can download showing all the codes you need to enter to make just about any kind of equation you want!