Question 393788
Use the equation f=4sqrt(A) to calculate the amount of fence f you need to buy
 based on the area A of the playground.
Suppose you want to increase the fenced play area to four times its current area.
 If you can reuse the fencing already at the park, how much new fencing do you need to buy? 
:
Let F = amt of fence you need to buy:
:
A = given area of the original playground
then
4A = area of new playground
:
Fence to buy = New fence length - old fence length
F = {{{4sqrt(4A) - 4sqrt(A)}}}
extract the square root of 4
F = {{{4*2sqrt(A) - 4sqrt(A)}}}
F = {{{8sqrt(A) - 4sqrt(A)}}}
Subtract like terms
F = {{{4sqrt(A)}}} amt of fence to be added, (the same amt you have)