SOLUTION: A garden area is 30ft long and 20ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400ft^2, what is the width of the path? Gosh I am so lo

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Question 65711: A garden area is 30ft long and 20ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400ft^2, what is the width of the path?
Gosh I am so lost on this one, thank you

Found 2 solutions by ptaylor, josmiceli:
Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!
A garden area is 30ft long and 20ft wide. A path of uniform width is set around the edge. If the remaining garden area is 400ft^2, what is the width of the path?
Let x= width of path
garden area=(l)(w)=(30)(20)=600 sq ft
remaining garden area=400 sq ft

Length of the remaining garden area =(30-2x) ft
Width of remaining garden area = (20-2x) ft, so
Eq(1) (30-2x)(20-2x)=400 expanding the factors, we have:
600-100x+4x^2=400 divide by 4
150-25x+x^2=100 subtract 100 from each side
x^2-25x+50=0 factors are:
Using the quadratic formula(x=(-b+or-sqrt(b^2-4ac))/2a we get
x=(25+or-sqrt(625-200))/2
x=(25+or-sqrt(425))/2
x=(25-20.6)/2
x=2.2 ft
x=(25+20.6)/2
x=22.8 ft Not a solution. It yields negative lengths and widths
Substitute x=2.2ft in (1) and we get
(30-4.4)(20-4.4)=400
(25.6)(15.6)=400
399+=400

Hope this helps----ptaylor

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The garden area is 30%2A20+=+600
When the path around it is made, 400 is left
for the garden
If the width of the path is x, the area, 400
is %2830+-+2x%29%2A%2820+-+2x%29
%2830+-+2x%29%2A%2820+-+2x%29+=+400
600+-+40x+-+60x+%2B+4x%5E2+=+400
4x%5E2+-100x+%2B+200+=+0
x%5E2+-+25x+%2B+50+=+0
solve with quadratic formula
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-%28-25%29+%2B-+sqrt%28+%28-25%29%5E2-4%2A1%2A50+%29%29%2F%282%2A1%29+
x+=+%2825+%2B-+sqrt%28625-200+%29%29%2F2+
x+=+%2825+%2B-+sqrt%28425%29%29%2F2+
x+=+%2825+%2B-+20.616%29%2F2
x+=+12.5+-+10.308
x+=+2.192 ft, answer
check
%2830+-+2x%29%2A%2820+-+2x%29+=+400
%2830+-+2%2A2.192%29%2A%2820+-+2%2A2.192%29+=+400
%2830+-+4.384%29%2A%2820+-+4.384%29+=+400
25.616%2A15.616+=+400
400+=+400
Unless I goofed, that's it