Answer:
[tex]A = 4x^2 + 86x + 450[/tex]
Step-by-step explanation:
Given
[tex]Walkway = x[/tex]
[tex]Length = 18[/tex]
[tex]Width = 25[/tex]
Required:
The area of the swimming pool
Assume the walkway will be on the 4 sides of the swimming pool.
The total length (L) of the swimming pool will be:
[tex]L = 18 + x + x[/tex]
[tex]L = 18 + 2x[/tex]
The total width (W) will be:
[tex]W = 25 + x + x[/tex]
[tex]W = 25 + 2x[/tex]
The area (A) is:
[tex]A = L * W[/tex]
[tex]A = (18 + 2x) * (25 + 2x)[/tex]
Expand bracket
[tex]A = 18 * 25 + 18 * 2x + 25 * 2x + 2x * 2x[/tex]
[tex]A = 450 + 36x + 50x + 4x^2[/tex]
[tex]A = 450 + 86x + 4x^2[/tex]
Reorder
[tex]A = 4x^2 + 86x + 450[/tex]
