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3 years ago

(a + 1)(a + 8) = 0 How to solve

Mathematics

2 answers:

stich3 [128]3 years ago

7 0

Answer:Since both terms are perfect cubes, factor using the difference of cubes formula,

−

(

−

)

(

)

where

and

(

−

)

(

⋅

)

Simplify.

Tap for more steps...

(

−

)

(

)

If any individual factor on the left side of the equation is equal to

, the entire expression will be equal to

−

Set the first factor equal to

and solve.

Tap for more steps...

Set the next factor equal to

and solve.

Tap for more steps...

−

√

−

√

The final solution is all the values that make

(

−

)

(

)

true.

−

√

−

√

Step-by-step explanation:

Marina CMI [18]3 years ago

7 0

(a + 1) (a + 8) = 0

a^2 + 8a + a + 8 = 0
a^2 + 9a + 8 = 0
a^2 + a + 8a + 8 = 0
a (a + 1) + 8 (a + 1) = 0
(a + 1) (a + 8) = 0

a + 1 = 0
a = -1

a + 8 = 0
a = -8

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According to a Washington Post-ABC News poll, 331 of 502 randomly selected U.S. adults interviewed said they would not be bother

k0ka [10]

Answer:

$z=\frac{0.659 -0.5}{\sqrt{\frac{0.5(1-0.5)}{502}}}=7.124$

$p_v =P(z>7.124)=5.24x10^{-13}$

So the p value obtained was a very low value and using the significance level given $\alpha=0.05$ we have $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of interest is significantly higher than 0.5.

Step-by-step explanation:

Data given and notation

n=502 represent the random sample taken

X=331 represent the adults that said they would not be bothered if the NAtional security agency

$\hat p=\frac{331}{502}=0.659$ estimated proportion of people who would not be bothered if the NAtional security agency

$p_o=0.5$ is the value that we want to test

$\alpha=0.01$ represent the significance level

Confidence=99% or 0.99

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 the true proportion is higher than the majority of 0.5:

Null hypothesis: $p\leq 0.5$

Alternative hypothesis: $p > 0.5$

When we conduct a proportion test we need to use the z statistic, 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:

$z=\frac{0.659 -0.5}{\sqrt{\frac{0.5(1-0.5)}{502}}}=7.124$

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 $\alpha=0.01$ . The next step would be calculate the p value for this test.

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

$p_v =P(z>7.124)=5.24x10^{-13}$

4 0

3 years ago

Write the inequality represented by each graph..

igomit [66]

Answer:

Step-by-step explanation:

HERE ARE THE ANSWERS

6 0

3 years ago

Salina, Tamara, and Uma are working on their homework together. Salina tells her friends that she got θ=52∘θ=52∘ for the inverse

svlad2 [7]

Answer:

The values reported by Uma, Salina, and Tamara are all possible values for inverse cosine

Step-by-step explanation:

Solution:-

- The solution to the inverse "cosine" problem would have a general form:

θ = cos^-1 ( a )

Where, a: Any arbitrary constant, - 1 < a < 1

- The value of θ = 52° was reported by Salina suggests that the answer lies in the first quadrant of a cartesian plane where ( sin (θ) , cos (θ) , tan (θ) ) have positive values for "a".

Hence, 0 < a < 1 , θ = 52°

- The value of θ = 128° was reported by Tamara suggests that the answer lies in the second quadrant of a cartesian plane where ( sin (θ) ) have positive values for "a" and (cos (θ) , tan (θ) have negative values for "a". So for cos (128):

Hence, -1 < a < 0 , θ = 128°

- The value of θ = 308° was reported by Uma suggests that the answer lies in the fourth quadrant of a cartesian plane where ( cos (θ) ) have positive values for "a" and (sin (θ) , tan (θ) have negative values for "a". So for cos (308):

Hence, 0 < a < 1 , θ = 308°

- The angle θ reported by Uma and Salina are similar solution because of property law of complementary angles:

cos (θ) = cos ( 360 - θ )

Where, θ = 52°, cos (52°) = cos( 308°) .. Uma and Salina conform

However, cos ( 180 - θ ) = - cos (θ)

cos(128) = - cos ( 52 ) .... Uma and Tamara conform.

5 0

3 years ago

To solve the equation x ^2 - 2x = 3 by the technique of completing the square, you would add 4 to each side of the equation as o

Karolina [17]

Answer:

x = -1

x = 3

Step-by-step explanation:

$\sf x^2 - 2x = 3$

Add 1 to both sides:

$\sf \implies x^2 - 2x+1 = 3+1$

Factor the left side:

$\sf \implies (x-1)^2 = 4$

Square root both sides:

$\sf \implies x-1 = \pm2$

Therefore:

$\sf \implies x-1=-2 \implies x=-1$

$\sf \implies x-1=2 \implies x=3$

6 0

3 years ago

What is 18 expressed as a percent?

Vladimir79 [104]

Here is your answer:

Your answer is 18%

Reason: That's because 18 has a invisible decimal point:

18.

Then you move to decimal and change it into a %

Which will make it 18%

Your answer is...
18%

3 0

3 years ago

Read 2 more answers