Find the measure of the hands of a clock at 12:38

Write the equation in standard form. Identity the center and radius.<br> x² + y2 + 8x-4y-7=0

lorasvet [3.4K]

Answer:

equation;

$(x + 4) {}^{2} + (y - 2) {}^{2} = 27$

Center (-4,2)

Radius is

$3 \sqrt{3}$

Step-by-step explanation:

Since the x^2 and y^2 have the same coeffiecent this will be a circle in a form of

$(x - h) {}^{2} + (y - k) {}^{2} = {r}^{2}$

Where (h,k) is center

r is the radius

So first we group like Terms together

${x}^{2} + 8x + {y}^{2} - 4y - 7 = 0$

Add 7 to both sides

${x}^{2} + 8x + {y}^{2} - 4y = 7$

$( {x}^{2} + 8x) +( {y}^{2} - 4y) = 7$

Since the orginal form of the equation of the circle has a perfect square we need to complete the square for each problem

$(\frac{8}{2} ) {}^{2} = 16$

and

$( - \frac{4}{2} ) {}^{2} = 4$

so we have

${x}^{2} + 8x + 16 + {y}^{2} - 4y + 4y = 7 + 16 + 4$

${x}^{2} + 8x + 16 + {y}^{2} - 4y + 4y = 27$

$(x + 4) {}^{2} + (y - 2) {}^{2} = 27$

To find our center, h is -4 and k is 2

so the center is (-4,2)

The radius is

$\sqrt{27} = 3 \sqrt{3}$

So the radius is 3 times sqr root of 3.

8 0

2 years ago

A tank can be filled by one pump in 3.2 hours and by another pump in 80 minutes. A third pump can drain the tank in 2 hours and

Mademuasel [1]

Answer:

Rounding to the nearest minute, it would take 95 minutes, or 1 hour and 35 minutes.

Step-by-step explanation:

Let's convert each time to minutes:

3.2 hours = 192 minutes

80 minutes = 80 minutes

2 hr 20 min = 140 minutes

Next, let's find the least common multiple:

LCM(192, 80, 140) = 6720

So let's say the volume of the tank is 6720 units. The speed of each pump is therefore:

Pump 1 = 6720 units / 192 minutes = 35 units/minute

Pump 2 = 6720 units / 80 minutes = 84 units/minute

Pump 3 = -6720 units / 140 minutes = -48 units/minute

Their combined speed is:

35 + 84 − 48 = 71 units/minute

So the time to fill the tank is:

6720 units / (71 units/minute) = 94.65 minutes

Rounding to the nearest minute, it would take 95 minutes, or 1 hour and 35 minutes.

6 0

3 years ago

Ali will rent a car for the weekend. He can choose one of two plans. The first plan has an initial fee of 70 and costs an additi

Aleksandr-060686 [28]

Answer: Ali would need to drive 350 miles for the two plans to cost the same.

Step-by-step explanation:

This question can be solved by creating two equations using the information supplied in the question and then solving these simultaneously.

Let the cost be C.

Let the number of miles be M.

Let the initial payment be i.

Let the rate per mile driven be R.

Plan 1:

C = i+R×M

C = 70+0.60M ... equation 1

Plan 2:

C = i+R×M

C = 0+0.80M

C = 0.80M ...equation 2

Substituting equation 2 into equation 1:

0.80M = 70+0.60M

0.80-0.60M = 70

0.20M = 70

M = 70/0.20

M = 350 miles

5 0

3 years ago

Find the missing terms in the<br>sequence 27, ? , 23, ? , 19,...<br>good luck

Vikki [24]

Is it subtract by 2? So I think it would be 27,25,23,21, 19

8 0

3 years ago

First answer gets a thanks

Karolina [17]

I would have to say A - Mean; because the data is skewed and there are outliers.

This is because the median of this would not be accurate for the number of kids that read no books and the random three kids that read ten. Mean, however, would find the true median within the plot and utilize and take into account the outliers and how skewed the data is.

Hope this helps!

7 0

3 years ago

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