Question 864642
Pool length, x.
Pool width, y.
2 = width of walkway.
x=2y; so let us say:
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2y = pool length, and y = pool width
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Total Area combined walkway and pool is {{{(2y+2*2)(y+2*2)}}}.
Pool Area is {{{2y^2}}}.
Walkway area is given, 196 square feet.
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Those three parts give you {{{Total=Pool+Walkway}}}:
{{{highlight_green((2y+4)(y+4)=2y^2+196)}}}.  This will be a quadratic equation.  Can you do the rest?