Answer:
- 12 ft parallel to the river
- 6 ft perpendicular to the river
Step-by-step explanation:
The least fence is used when half the total fence is parallel to the river. That is, the shape of the rectangle is twice as long as it is wide.
72 = W(2W)
36 = W²
6 = W . . . . . . the width perpendicular to the river
12 = 2W . . . . the length parallel to the river
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<em>Development of this relation</em>
Let T represent the total length of the fence for some area A. Then if x is the length along the river, the width is y=(T-x)/2, and the area is ...
A = xy = x(T -x)/2
Note that the equation for area is that of a parabola with zeros at x=0 and at x=T. That is, for some fence length T, the area will be a maximum at the vertex of this parabola. That vertex is located halfway between the zeros, at ...
x = (0 +T)/2 = T/2
The corresponding area width (y) is ...
y = (T -T/2)/2 = T/4
Equivalently, the fence length T will be a minimum for some area A when x=T/2 and y=T/4. This is the result we used above.
The answer is: [B]: " 9 * 10⁻³ " .
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The answer for this question when grouping:
(x+2)(3x^2+1)
she bought 10 pencils and 5 erasers
Let x represent the number of pencils and y represent the number of erasers.
Gabby wants to spend exactly $2.00 on pencils and erasers, hence:
0.15x - 0.1y = 2 (1)
Therefore x = 10 and y = 5
Therefore she bought 10 pencils and 5 erasers.
Find out more at: brainly.com/question/25035724
Answer:
Step-by-step explanation:
triangle value- 180 degrees
since the two bottom angles are alike
62+62= 124
180-124=54
