(4.2 x 10^8) x (2.8 x 10^−2)
1 answer:
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Answer:
<h2>The lengths of the bases of the trapezoid:</h2><h2>42/h cm and 84/h cm.</h2>Step-by-step explanation:
The formula of an area of a triangle:
<em>b</em><em> </em>- base
<em>h</em> - height
We have <em>b = 21cm, h = 6cm</em>.
Substitute:
The formula of an area of a trapezoid:
<em>b₁, b₂</em> - bases
<em>h</em><em> - </em>height
We have <em>b₁ = 2b₂</em>, therefore <em>b₁ + b₂ = 2b₂ + b₂ = 3b₂</em>.
The area of a triangle and the area of a trapezoid are the same.
Therefore
<em>multiply both sides by 2</em>
<em>divide both sides by 3</em>
<em>divide both sides by h</em>
Answer:
There is no minimum cost for the fencing that can satisfy these conditions.
as the equation obtained for this problem is y = .
Step-by-step explanation:
let length of the rectangular rose garden be x
and breath of the rectangular rose garden be y
then the area of the garden = xy
cost of fencing a foot for the 3 non road sides = $6
and cost of fencing a foot for a road side = $8
total cost of fencing = 6x + 8x + 6y + 6y
so, total cost = 14x + 12y
cost of fencing for every square foot of the area =$2
So, 2xy = 14x + 12y
=> 2xy = 14x + 12y
Also, x and y has to satisfy x>0 and y>0
You can solve for y (or x if you prefer)
2xy-12y=14x
xy - 6y = 7x
y(x-6)=7x
y =
we can check that this function has no minimum value.
as we increase x (starting any x > 6 to make y positive) to make y minimal, y will decrease but the product xy will increase.
So, there is not a minimum cost for fencing that can satisfy these conditions.