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Montano1993 [528]

3 years ago

15

Be Precise, One kilometer is About 0.62 mile.

1 answer:

ahrayia [7]3 years ago

4 0

Answer:

about 7.4 miles

exact is 7.44 miles

Step-by-step explanation:

0.62×12=7.44

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What is the x integer for the equation y=3x- 2

Aleksandr [31]

Answer:

maybe x=0=>y=1 or maybe x=0=>y=-2

8 0

3 years ago

Solve for p: a = 2πpw

MaRussiya [10]

Hello there.

<span>Solve for p: a = 2πpw

</span> $\frac{a}{6.283185w
}$

4 0

3 years ago

How is it that a square is a rectangle but a rectangle ins't a square?

Helen [10]

Beacuse <span>A square by definition is a "plane figure having four equal sides." Rectangles' sides are not equal and hence cannot be a square.

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5 0

3 years ago

Read 2 more answers

Help this is due today and I don’t know how to do it you please show me the steps:)

DochEvi [55]

Answer:

628 inches²

Step-by-step explanation:

the equation for surface area is SA=2(lw+lh+hw) so..

1. 2×(16×14 + 16×3 + 3×14)

2. 2×(224+48+42)

3. 2×314

4. 628

Hope this helps! :)

7 0

3 years ago

The base of an aquarium with given volume V is made of slate and the sides are made of glass. If the slate costs seven times as

lubasha [3.4K]

Answer:

$l = \sqrt[3]{\frac{2V}{7}}$ $b = \sqrt[3]{\frac{2V}{7}}$ $h = \sqrt[3]{\frac{49V}{4}}$

Step-by-step explanation:

Represent the volume of the box with V and the dimensions with l, b and h.

The volume (V) is:

$V = l * b * h$

Make h the subject of the formula

$h = \frac{V}{lb}$

The surface area (S) of the aquarium is:

$S = lb + 2(lh + bh)$

Where lb represents the area of the base (i.e. slate):

The cost (C) of the surface area is:

$C = 7 * lb + 1 * 2(lh + bh)$

$C = 7lb + 2(lh + bh)$

$C = 7lb + 2h(l + b)$

Substitute $\frac{V}{lb}$ for h in the above equation

$C = 7lb + 2*\frac{V}{lb}(l + b)$

$C = 7lb + \frac{2V}{lb}(l + b)$

$C = 7lb + \frac{2V}{b} + \frac{2V}{l}$

Differentiate with respect to l and with respect to b

$C_l=7b - \frac{2V}{l^2}$ $=0$

$C_b=7l - \frac{2V}{b^2}$ $=0$

To solve for b and l, we equate both equations and set l to b (to minimize the cost)

$7b - \frac{2V}{l^2}=7l - \frac{2V}{b^2}$

$7l - \frac{2V}{l^2}=7b - \frac{2V}{b^2}$

By comparison:

$l =b$

$C_l=7b - \frac{2V}{l^2}$ $=0$ becomes

$7l - \frac{2V}{l^2}=0$

$7l = \frac{2V}{l^2}$

Cross Multiply

$7l^3 = 2V$

Solve for l

$l^3 = \frac{2V}{7}$

$l = \sqrt[3]{\frac{2V}{7}}$

Recall that: $l =b$

$b = \sqrt[3]{\frac{2V}{7}}$

Also recall that:

$h = \frac{V}{lb}$

$h = \frac{V}{\sqrt[3]{\frac{2V}{7}}*\sqrt[3]{\frac{2V}{7}}}$

$h = \frac{V}{\sqrt[3]{\frac{4V^2}{49}}}$

Apply law of indices

$h = \sqrt[3]{\frac{49V^3}{4V^2}}$

$h = \sqrt[3]{\frac{49V}{4}}$

The dimension that minimizes the cost of material of the aquarium is:

$l = \sqrt[3]{\frac{2V}{7}}$ $b = \sqrt[3]{\frac{2V}{7}}$ $h = \sqrt[3]{\frac{49V}{4}}$

8 0

3 years ago