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3 years ago

Can someone solve the system of equations?

Mathematics

1 answer:

kogti [31]3 years ago

5 0

Y=x^2-5

y=2x-5
y+5=2x
x=(y+5)/2

y=((y+5)/2)^2-5
y=(y^2+10y+25)/4-5
4y=y^2+10y+25-20
0=y^2+6y+5
0=(y+5)(y+1)
y= -5 or -1

y=2x-5 (y= -5 doesn't work for this one so use -1)
-1=2x-5
2x=4
x=2

Using these answers, you can choose answer D with reasonable certainty.

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Me need help math';;''';';';'

QveST [7]

Answer:

Adjacent angles

Step-by-step explanation:

They share a common vertex and side, fulfilling the criteria that makes them adjacent angles.

Sorry, needed to make up characters lol.

3 0

3 years ago

Read 2 more answers

A random sample of size n1= 25, taken from a normal population with a standard deviation σ1= 5, has a mean X1= 80. A second rand

sesenic [268]

Answer:

The 94% confidence interval would be given by $2.898 \leq \mu_1 -\mu_2 \leq 7.102$

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X_1 =80$ represent the sample mean 1

$\bar X_2 =75$ represent the sample mean 2

n1=25 represent the sample 1 size

n2=36 represent the sample 2 size

$\sigma_1 =5$ sample standard deviation for sample 1

$\sigma_2 =3$ sample standard deviation for sample 2

$\mu_1 -\mu_2$ parameter of interest.

The confidence interval for the difference of means is given by the following formula:

$(\bar X_1 -\bar X_2) \pm z_{\alpha/2}\sqrt{\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2}}$ (1)

The point of estimate for $\mu_1 -\mu_2$ is just given by:

$\bar X_1 -\bar X_2 =80-75=5$

Since the Confidence is 0.94 or 94%, the value of $\alpha=0.06$ and $\alpha/2 =0.03$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.03,0,1)".And we see that $z_{\alpha/2}=1.88$

The standard error is given by the following formula:

$SE=\sqrt{\frac{\sigma^2_1}{n_1}+\frac{\sigma^2_2}{n_2}}$

And replacing we have:

$SE=\sqrt{\frac{5^2}{25}+\frac{3^2}{36}}=1.118$

Confidence interval

Now we have everything in order to replace into formula (1):

$5-1.88\sqrt{\frac{5^2}{25}+\frac{3^2}{36}}=2.898$

$5+1.8\sqrt{\frac{6^2}{36}+\frac{7^}{49}}=7.102$

So on this case the 94% confidence interval would be given by $2.898 \leq \mu_1 -\mu_2 \leq 7.102$

7 0

3 years ago

A baker is selling a ton of pies. She puts them in crates and boxes. There are 65 crates and 121 boxy. Each crate contains 43 ap

marta [7]

Let's first find the number of apple pies.

apple pies = 65 crates x 43 apple pies per crate = 2795 apples pies

If each apple pie cost $12 then...

money from apple pies = 2795 apple pies x $12 = $33540

total pies sold = 2795 apple pie + 121 boxes x 76 sweet potato pies = 11991 pies

4 0

3 years ago

Read 2 more answers

Help please!!!!!!!!!!!!!!!!

ankoles [38]

All you would have to do is substitute!
Answer:

First one will be 2
Second one will be 10
Third one will be undefined

Explanation:
So for the first one you are substituting x for -3 so then the equation would look like this: -3^2+9/-3^2, this will equal to 9+9/9 which your answer would be 2 since 18/9 is 2. For the second one it will look like this -1^2+9/-1^2 which would be 1+9/1, this would equal to 10. For the last one it will look like this 0^2+9/0^2 which would just be 0+9/0 9/0 would be undefined.

5 0

3 years ago

If today is friday what day of the week will it be 101 days from today

lys-0071 [83]

If the date were to be October 23rd, 2015.. In 101 days, it would be a Monday. -J

4 0

3 years ago