help please!! i really don’t understand how to do this and i just need an answer so i can get this class over with ;;

You need to solve a system of equations. You decide to use the elimination method. Which of these is not allowed?

Serggg [28]

Answer:

B

Step-by-step explanation:

The <u>Elimination Method</u> is the method for solving a pair of linear equations which reduces one equation to one that has only a single variable.

If the coefficients of one variable are opposites, you add the equations to eliminate a variable, and then solve.
If the coefficients are not opposites, then we multiply one or both equations by a number to create opposite coefficients, and then add the equations to eliminate a variable and solve.

When multoplying the equation by a coefficient, we multiply both sides of the equation (multiplying both sides of the equation by some nonzero number does not change the solution).

So, option B is not allowed (it is not allowed to multiply only one part of equation)

8 0

3 years ago

A small child is at a candy store, eager to spend his $1 allowance on candy. His two favorite candies are priced at $0.05 and $0

melisa1 [442]

While both a and c work the most likely answer that they want would be A because it represent the cents already and it shows all possible ways that those two values can be split among 1 dollar

3 0

3 years ago

Read 2 more answers

8. A cellphone company charges $29.99 per month for the first 500 minutes of calls and $0.30 a minute for any calls over the 500

scZoUnD [109]

Answer:

C) $64.49

Step-by-step explanation:

let 'x' = #minutes

cost = 29.99 + 0.3(x-500)

= 29.99 + .3(115)

= 29.99 + 34.50

= $64.49

8 0

3 years ago

What the answer is and how?

sladkih [1.3K]

Answer:

PerimeterFigure= pi*DIameter/2= 1.5*pi ft.

Step-by-step explanation:

The perimeter is the length of the figure, since we are dealing with an semi-circle, we can use the perimeter equation for a full circle and divide it by half.

Perimeter= 2pi*R= pi*Diameter.

Since Our figure is a semi circle, as we say earlier, we now will divide the above result by half.

PerimeterFigure= pi*DIameter/2= 1.5*pi ft.

3 0

2 years ago

Test the hypothesis using the P value approach. Be sure the verify the requirements of the test.

Andreas93 [3]

Answer:

$p_v =2*P(z$

If we compare the p 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 is not significantly different from 0.77.

Step-by-step explanation:

1) Data given and notation

n=500 represent the random sample taken

X=380 represent the number of people with some characteristic

$\hat p=\frac{380}{500}=0.76$ estimated proportion of adults that said that it is morally wrong to not report all income on tax returns

$p_o=0.76$ 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)

2) Concepts and formulas to use

We need to conduct a hypothesis in order to test the claim that the true proportion is 0.7 .:

Null hypothesis: $p=0.77$

Alternative hypothesis: $p \neq 0.77$

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 $p_o$ .

<em>Check for the assumptions that he sample must satisfy in order to apply the test </em>

a)The random sample needs to be representative: On this case the problem no mention about it but we can assume it.

b) The sample needs to be large enough

$np_o =500*0.77=385>10$

$n(1-p_o)=384*(1-0.77)=115>10$

3) Calculate the statistic

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

$z=\frac{0.76-0.77}{\sqrt{\frac{0.77(1-0.77)}{500}}}=-0.531$

4) 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 bilateral test the p value would be:

$p_v =2*P(z$

If we compare the p 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 is not significantly different from 0.77.

6 0

3 years ago