Question 327454
A rectangular pool is surrounded by a walk 4 meters wide.
 The pool is 6 meters longer than its width.
 If the total area is 576 square meters more than the area of the pool,
 find the dimensions of the pool.
:
Let x = the width of the pool
then
(x+6) = length of the pool
:
Find the area (a) of the pool
a = x(x+6)
a = x^2 + 6x; area of the pool only
:
The dimensions of the area including the 4' walkway (add 8 to each dimension)
(x+8) = overall width
(x+14) = overall length
:
Find the area (A) including the 4m walkway
FOIL: (x+8)(x+14)
A = x^2 + 22x + 112; the total area
:
"If the total area is 576 square meters more than the area of the pool,"
(x^2 + 22x + 112) - (x^2 + 6x) = 576
remove the brackets
x^2 + 22x + 112 - x^2 - 6x = 576
results
22x - 6x = 576 - 112
:
16x = 464
x = {{{464/16}}}
x = 29 m is the width of the pool
then
29 + 6 = 35 m is length
:
:
Check solution using x=29
29(29+6) = 1015 pool area
(29+8)(29+14) = 1591 overall area
1591 - 1015 = 576; confirms our solution