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3 years ago

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If it takes Laine 3 hours to wash the windows, Leslie 4 hours to wash the same windows, and Lance 5 hours to wash the windows, h

ow long would it take them all working together?
0.78 hours
1.3 hours
2.6 hours
5 hours

1 answer:

pentagon [3]3 years ago

4 0

Answer:

Step-by-step explanation: 0.78 hours

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In a solar system, two comets pass near the sun, which is located at the origin. Comet E is modeled by quantity y plus 16 end qu

Leya [2.2K]

Explanation:

The equation of comet E is given below as

$\frac{(y+16)^2}{400}+\frac{x^2}{144}=1$

The equation of comet H is modelled below as

$\frac{(y+13)^2}{144}-\frac{x^2}{25}=1$

Given, that the Sun is located at the origin.

This is an equation of an ellipse. So, the path traveled by Comet e is an elliptic path.

Comparing with the Standard equation of ellipse: below,we will have

$\frac{(y-k)^2}{b^2}+\frac{(x-h)^2}{a^2}$

Whise center is

$\begin{gathered} center=(h,k) \\ vertices=(h\pm a,0) \end{gathered}$

By comparing coefficient, we will have

$\begin{gathered} a^2=144 \\ a=12 \\ b^2=400 \\ b=20 \\ k=-16 \\ h=0 \\ (h,k)=(0,-16) \end{gathered}$

Hence,

The vertex of comet E will be

$\begin{gathered} (h\pm a,0) \\ (0+12,0),(0-12,0) \\ (12,0),(-12,0) \end{gathered}$

The vertex of comet E is

$(12,0),(-12,0)$

Part C:

It is the foci forboth comets

$\begin{gathered} cometE: \\ c=\sqrt{b^2-a^2} \\ c=\sqrt{400-144} \\ c=\sqrt{256} \\ c=16 \\ \\ For\text{ comet F:} \\ c=\sqrt{a^2-b^2} \\ c=\sqrt{144+25} \\ c=\sqrt{169} \\ c=13 \end{gathered}$

Hence,

The foci will be

$\begin{gathered} (16\pm16,0) \\ cometE \\ (0,0),(32,0) \\ cometF: \\ (13\pm13,0) \\ (0,0),(26,0) \end{gathered}$

5 0

1 year ago

Find the volume of this sphere. Use 3 for pi.

Otrada [13]

Answer:

radius=16divided by 2

=8

Volume=4÷3πr^3

Volume=4÷3×3×8

Volume=96÷3

Volume=32

4 0

3 years ago

If 9a+8b+9c=-9 what is 81c+72b+ 81a

vivado [14]

The answer is -234

Have a fantastical day

4 0

3 years ago

Read 2 more answers

What is the value of x? <br> 3x + (6x - 6) = 4(2x-2)

olya-2409 [2.1K]

Answer:

x = -2

Step-by-step explanation:

To start, let's add on the first side to get 3x + 6x - 6 = 9x - 6. For the second side, we need to distribute the 4 to get 4(2x) + 4(-2), or 8x + (-8) or 8x - 8. Setting these equal, we subtract 8x from both sides to get x - 6 = -8, and adding 6 to both sides gives x = -2.

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3 years ago

Use the area to find the radius. If you could include steps that’ll be very helpful :)

Marizza181 [45]

Answer:

Radius = 13 m

Step-by-step explanation:

Formula for area of circle is given as:

$A = \pi {r}^{2} \\ \\ \therefore \: 169\pi \: = \pi {r}^{2} \\ \\ \therefore \: {r}^{2} = \frac{169\pi }{\pi} \\ \\ \therefore \: {r}^{2} = 169 \\ \\ \therefore \: {r} = \pm \sqrt{169} \\ \\\therefore \: r = \pm \: 13 \: m \\ \\ \because \: radius \: of \: a \: circle \: can \: not \: be \: a \: negative \: \\quantity \\ \\ \huge \red{ \boxed{\therefore \: r = 13 \: m }}$

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3 years ago