You can
put this solution on YOUR website! I have a rectangular garden with dimensions of 30' by 40'. The total garden area is 1800 ft^2. I am trying to figure the constant width of the surrounding walkway.
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If the garden is 30 x 40 its area is 1200 sq ft.
The 1800 sq ft must refer to the garden area plus
the area of the sidewalk which surrounds the garden
area.
The sidewalk area must be 600 sq. ft.
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Draw the picture. The sidewalk is composed of four
rectangles.
TWO are (40+2x)*x each or a total of 2x(40+2x) sq ft.
The other TWO are 30 * x each or a total of 2(30x)=60x sq. ft.
EQUATION:
2x(40+2x)+60x=600
80x+4x^2+60x=600
4x^2+140x-600=0
x^2+35x-150=0
x=[-35+sqrt(35^2-4(-150)]/2
x=3.86 ft. (width of the sidewalk.
Cheers,
Stan H.