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LiRa [457]
3 years ago
7

Solve the system of equations. 1) X + y = 5 2x - y = 7 2) 3x+y=7 -7-5y=25

Mathematics
2 answers:
ololo11 [35]3 years ago
8 0

Answer:

1) x = 6, y = - 1

2) x = 4.4667, y = -6.4

Step-by-step explanation:

1)

x + y = 5

2x - y = 7

First, let's solve for x using the first equation.

x + y = 5

x = -y + 5

Next, let's substitute the x value into the second equation.

2x - y = 7

2(-y + 5) - y = 7

-2y + 10 - y = 7

-2y - y + 10 = 7

-3y = -3

y = -1

Now, let's substitute y into the first equation.

x + y = 5

x + (-1) = 5

x = 6

Therefore, x = 6, y = -1

2) 3x + y = 7

-7 - 5y = 25

First, let's solve for y in the second equation.

-7 - 5y = 25

-5y = 32

y = -6.4 or y = -6 \frac{2}{5} or y = -\frac{32}{5}

Next, let's substitute the y value into the second equation.

3x + y = 7

3x +(-6.4) = 7

3x = 13.4

x = 4.4667 (answer is rounded) or x = 4\frac{14}{30} or x = \frac{134}{30}

Therefore, x = 4.4667, y = -6.4

Hope this helped <3

Oliga [24]3 years ago
3 0

Answer:

1) <em>X </em> +  <em>y</em>  =  5 ,  2<em> x</em>  −  <em>y </em> =  7

2) <em>x</em>  =  67 /15, <em>y</em> = -32/5

Step-by-step explanation:

  1. Solve for <em>y</em> in the first equation
  2. Replace all occurencies of <em>y</em> with -32/5 in each equation
  3. Then solve for the first equation

<u>The solution to the system is the complete set of ordered pairs that are valid solutions, and the result can be shown in multiple forms.</u>

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Step-by-step explanation:

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In a study of the accuracy of fast food drive-through orders, McDonald’s had 33 orders that were not accurate among 362 orders o
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Answer:

A. We need to conduct a hypothesis in order to test the claim that the true proportion of inaccurate orders p is 0.1.

B. Null hypothesis:p=0.1  

Alternative hypothesis:p \neq 0.1  

C. z=\frac{0.0912 -0.1}{\sqrt{\frac{0.1(1-0.1)}{362}}}=-0.558  

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F. 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 true proportion of inaccurate orders is not significantly different from 0.1.  

Step-by-step explanation:

Data given and notation

n=362 represent the random sample taken

X=33 represent the number of orders not accurate

\hat p=\frac{33}{363}=0.0912 estimated proportion of orders not accurate

p_o=0.10 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)  

A: Write the claim as a mathematical statement involving the population proportion p

We need to conduct a hypothesis in order to test the claim that the true proportion of inaccurate orders p is 0.1.

B: State the null (H0) and alternative (H1) hypotheses

Null hypothesis:p=0.1  

Alternative hypothesis:p \neq 0.1  

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)  

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C: Find the test statistic

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D: Find the critical value(s)

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P value

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

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E: Would you Reject or Fail to Reject the null (H0) hypothesis.

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