Which are the solutions of x2 = −7x

(giving brainiest)

Andreas93 [3]

Answer:

b.

Step-by-step explanation:

4 0

3 years ago

Consider the system of equations. y = −2x + 4 y = − 1/3x − 1

ipn [44]

Hey there! I'm happy to help!

We have two values for y. Since y=y, this means that −2x + 4 and − 1/3x − 1 are equal as well, so we can put them in an equation and solve for x.

−2x + 4 = − 1/3x − 1

We subtract 4 from both sides.

-2x=-1/3x-5

We add 1/3 x to both sides.

-5/3x=-5

We divide both sides by -1 2/3.

x=3

Now, we plug this into one of the original equations to find y.

y=-2(3)+4

y=-6+4

y=-2

Therefore, the solution is (3,-2) or x=3 and y=-2.

I hope that this helps! Have a wonderful day! :D

4 0

3 years ago

A manufacturer of a new medication on the market for Alzheimer's disease makes a claim that the medication is effective in 65% o

NeX [460]

Answer:

$z=\frac{0.639 -0.65}{\sqrt{\frac{0.65(1-0.65)}{180}}}=-0.309$

$p_v =P(z$

So the p value obtained was a very high value and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the proportion of adults with the medication was effective is not significantly less than 0.65

Step-by-step explanation:

Data given and notation

n=180 represent the random sample taken

X=115 represent the adults with the medication was effective

$\hat p=\frac{115}{180}=0.639$ estimated proportion of adults with the medication was effective

$p_o=0.65$ is the value that we want to test

$\alpha=0.05$ represent the significance level

Confidence=95% or 0.95

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

Concepts and formulas to use

We need to conduct a hypothesis in order to test the claim that true proportion is less than 0.65.:

Null hypothesis: $p \geq 0.65$

Alternative hypothesis: $p < 0.65$

When we conduct a proportion test we need to use the z statisitc, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.639 -0.65}{\sqrt{\frac{0.65(1-0.65)}{180}}}=-0.309$

Statistical decision

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

The significance level provided $\alpha=0.05$ . The next step would be calculate the p value for this test.

Since is a left tailed test the p value would be:

$p_v =P(z$

So the p value obtained was a very high value and using the significance level given $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 5% of significance the proportion of adults with the medication was effective is not significantly less than 0.65

3 0

3 years ago

Betsy's mom likes to bake.

Amanda [17]

Answer:

No

Step-by-step explanation:

I did it

4 0

3 years ago

Read 2 more answers

Write the equation of the line in slope-intercept that has slope m= -4 and y- intercept b=8<br><br>