Sasha is planning a new rectangular garden 20m by 30m. She plans to build a walkway, ( more below)? - rectangular garden
Sasha is working on a new rectangular garden 20 m by 30m. It plans to build a bridge, build a uniform width around garden. The budget is $ 6000, and she knows that building it costs $ 10/m2 the bridge. How far can the gateway?
Friday, February 19, 2010
Rectangular Garden Sasha Is Planning A New Rectangular Garden 20m By 30m. She Plans To Build A Walkway, ( More Below)?
4 comments:
Let x width.
Open 6000/10 = 600 m ^ 2
(2x 30) (2x +20) = 30 * 20 + 6000/10
4x ^ 2 + 100x + 600 = 1200
x ^ 2 + 25x - 150 = 0
(x + 30) (x - 5) = 0
if x> 0 is not
width = x = 5 m
The total area of soil = 6000/10 = 600 sqm
Gang offers a wide x
On both sides, the area is by any route (30 + 2x) * x, short in the area of each side x 20 *
Total = 2 * [(30 +2 x) * x + 20x] = 600
[(30 +2 x) * x + 20x] = 300
30x + 2x ^ 2 + 20x = 300
2x ^ 2 + 50x - 300 = 0
x ^ 2 + 25x - 150 = 0
(x-5) (x 30) = 0
x = 5 or x = -30
negative solution has no meaning when x = 5
Gateway 5 m wide
Time:
2 strips of 40 meters by 5 meters = 400 m ^ 2
2 strips of 20 m by 5 m = 200 m ^ 2
Total = 600 m ^ 2 * $ 10 = $ 6000
Note: The response of 6m above worng, because the curves were not taken into account.
Another possibility is that you can do to add the perimeter --r = 2 * (30 +20) = 100 m
Multiplied by the x Width: 100x
Add 4 corners = 4x ^ 2
and 4x ^ 2 + 100x = 600
Divided by 4:
x ^ 2 + 25x - 150 = 0, as previously
path = area of cost-speed = 6000 $ / ($ 10 / m ^ 2) = 600 m ^ 2
Review
Garden Area 30mx20m = 600m ^ 2
Total = Garden Route = 600 ^ 2 + 600 m ^ 2 = 1200 m ^ 2
= (30 + 10 m) (20 + 10)
gauge = 10m
If the lane width x meters
then the surface of the bridge is as follows:
A = 2 * 20x + 2 * 30x
A = 100x ²
so
Cost = 10 * x100 = 6000
x = 6 m
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