SOLUTION: the robertsons put a rectangular pool with a stone walkway around it in their backyard. the total lenghth of the pool and walkway is 3 times the total width.the walk way is 2 feet

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: the robertsons put a rectangular pool with a stone walkway around it in their backyard. the total lenghth of the pool and walkway is 3 times the total width.the walk way is 2 feet      Log On


   



Question 292629: the robertsons put a rectangular pool with a stone walkway around it in their backyard. the total lenghth of the pool and walkway is 3 times the total width.the walk way is 2 feet all around.
a. WRITE AN EXPRESSION FOR THE AREA OF THE POOL
B FIND THE AREA OF THE POOL WHEN THE TOTAL WIDTH IS 10FT
C FIND THE AREA OF THE POOL WHEN TE WIDTH IS 9 FT.

Answer by texttutoring(324) About Me  (Show Source):
You can put this solution on YOUR website!
This would be easier to explain if I could draw a picture, but I'll try to explain it with words.

Let w = total width of pool and walkway
the total length of the pool and walkway is 3 times the width, so it is l=3w
To find the length of the pool, we have to subtract 4 (2 feet from each end).

So length of pool=L=3w-4

Similarly, the width of the pool is W=w-4
a) The area of the pool is A = LW = (3w-4)(w-4)
b) if the total width is 10 feet, then that means w=10
A=(3w-4)(w-4)
A=(3*10-4)(10-4)
A=(30-4)(6)
A=26*6
A=156 ft^2

c) If the total width is 9 feet:
A=(3w-4)(w-4)
A=(3*9-4)(9-4)
A=(27-4)(5)
A=23*5
A=115 ft^2