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3 years ago

Estimate the sum: 6.74 + 6.92 + 7.243 + 7.398

Mathematics

1 answer:

hoa [83]3 years ago

4 0

Answer:

Step-by-step explanation:

6.74 and 6.92 both round up to 7. Meaning the problem is basically 7 time 4.

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How to do this problem

gavmur [86]

I forget sorry I’m very sorry I don’t even know elegy I commented

4 0

3 years ago

A circle has the equation 2x²+12x+2y²−16y−150=0.

KonstantinChe [14]

Answer: B. The coordinates of the center are (-3,4), and the length of the radius is 10 units.

Step-by-step explanation:

The equation of a circle in the center-radius form is:

$(x-h)^{2} +(y-k)^{2}=r^{2}$ (1)

Where $(h,k)$ are the coordinates of the center and $r$ is the radius.

Now, we are given the equation of this circle as follows:

$2x^{2}+12x+2y^{2}-16y-150=0$ (2)

And we have to write it in the format of equation (1). So, let's begin by applying common factor 2 in the left side of the equation:

$2(x^{2}+6x+y^{2}-8y-75)=0$ (3)

Rearranging the equation:

$x^{2}+6x+y^{2}-8y=75$ (4)

$(x^{2}+6x)+(y^{2}-8y)=75$ (5)

Now we have to complete the square in both parenthesis, in order to have a perfect square trinomial in the form of $(a\pm b)^{2}=a^{2}\pm+2ab+b^{2}$ :

For the first parenthesis:

$x^{2}+6x+b^{2}$

We can rewrite this as:

$x^{2}+2(3)x+b^{2}$

Hence in this case $b=3$ and $b^{2}=9$ :

$x^{2}+2(3)x+3^{2}=x^{2}+6x+9=(x+3)^{2}$

For the second parenthesis:

$y^{2}-8y+b^{2}$

We can rewrite this as:

$y^{2}-2(4)y+b^{2}$

Hence in this case $b=-3$ and $b^{2}=9$ :

$y^{2}-2(4)y+4^{2}=y^{2}-8y+16=(y-4)^{2}$

Then, equation (5) is rewritten as follows:

$(x^{2}+6x+9)+(y^{2}-8y+16)=75+9+16$ (6)

Note we are adding 9 and 16 in both sides of the equation in order to keep the equality.

Rearranging:

$(x-3)^{2}+(y-4)^{2}=100$ (7)

At this point we have the circle equation in the center radius form $(x-h)^{2} +(y-k)^{2}=r^{2}$

Hence:

$h=-3$

$k=4$

$r=\sqrt{100}=10$

8 0

3 years ago

4,0000000000×10,00000000

Mademuasel [1]

Answer:

yes 40

Step-by-step explanation:

she got it correct

4 0

3 years ago

Helllppppppppp

Lana71 [14]

Answer:

x = 45, y = 90

x = 60, y = 75

x = 25, y = 110

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

A major traffic problem in the Greater Cincinnati area involves traffic attempting to cross the Ohio River from Cincinnati to Ke

yaroslaw [1]

Answer:

a. 0.563 = 56.3% probability that for the next 60 minutes (two time periods) the system will be in the delay state.

b. 0.625 = 62.5% probability that in the long run the traffic will not be in the delay state

Step-by-step explanation:

Question a:

The probability of finding a traffic delay in one period, given a delay in the preceding period, is 0.75.

The system currently is in traffic delay, so for the next time period, 0.75 probability of a traffic delay. If the next period is in a traffic delay, the following period will also have a 0.75 probability of a traffic delay. So

0.75*0.75 = 0.563

0.563 = 56.3% probability that for the next 60 minutes (two time periods) the system will be in the delay state.

b. What is the probability that in the long run the traffic will not be in the delay state? If required, round your answers to three decimal places.

If it doesn't have a delay, 85% probability of continuing without a delay.

If it has a delay, 75% probability of continuing with a delay.

So, for the long run:

x: current state

85% probability of no delay if x is in no delay, 100 - 75 = 25% if x is in delay(1-x). So

$0.85x + 0.25(1 - x) = x$