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iren [92.7K]
4 years ago
15

i need help with number 7. its solving systems of equations by substitution. please show work!!! i need help

Mathematics
1 answer:
SCORPION-xisa [38]4 years ago
6 0
-4x+y=6
-5x-y=21

Solve for one side of either equation. I will use the first equation and solve for y.

-4x+y=6
+4x +4x

Y=4x+6
-5x-y=21

Now when you substitute, make sure to distribute properly including the easily missed negative.

-5x-(4x+6)=21
-5x-4x-6=21
-9x-6=21
-9x=27
X=27/-9

X=-3


Now that you know X, substitute to find Y.

Y=4(-3)+6
Y=-12+6

Y=-6

So your final answer is:
X=-3 Y=-6
(-3,-6)
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Suppose 241 subjects are treated with a drug that is used to treat pain and 54 of them developed nausea. Use a 0.05 significance
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Answer:

Null Hypothesis, H_0 : p = 0.20  

Alternate Hypothesis, H_a : p > 0.20  

Step-by-step explanation:

We are given that 241 subjects are treated with a drug that is used to treat pain and 54 of them developed nausea.

We have to use a 0.05 significance level to test the claim that more than 20​% of users develop nausea.

<em>Let p = population proportion of users who develop nausea</em>

So, <u>Null Hypothesis,</u> H_0 : p = 0.20  

<u>Alternate Hypothesis</u>, H_a : p > 0.20  

Here, <u><em>null hypothesis</em></u> states that 20​% of users develop nausea.

And <u><em>alternate hypothesis</em></u> states that more than 20​% of users develop nausea.

The test statistics that would be used here is <u>One-sample z proportion</u> test statistics.

                     T.S. =  \frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }   ~ N(0,1)

where,  \hat p = proportion of users who develop nausea in a sample of 241 subjects =  \frac{54}{241}  

             n = sample of subjects = 241

So, the above hypothesis would be appropriate to conduct the test.

6 0
3 years ago
Which expression has a value of 507<br> O A. 2x52<br> B. 2 x 55<br> C. 5 x 52<br> D. 5x25
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Answer:

.............,...........,.......................... ans is b

7 0
3 years ago
Question 7 (points) ∠DBC ≅ True or False
muminat

Answer:

answer is false okkkkm

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3 years ago
Help me solve this problem please
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Answer:

c. direct variation

Step-by-step explanation:

4 0
3 years ago
A group of 266 persons consist of men, women, and children. There are four times as many men as children. And twice as many wome
lara [203]

There are 152 men, 76 women and 38 children.

Step-by-step explanation:

Total persons = 266

Let,

men = m

women = w

children = c

According to given statement;

m+w+c=266    Eqn 1

m = 4c   Eqn 2

w = 2c   Eqn 3

Putting value of m and w from Eqn 2 and 3 in Eqn 1

4c+2c+c=266\\7c=266\\

Dividing both sides by 7

\frac{7c}{7}=\frac{266}{7}\\c=38

Putting c=38 in Eqn 2;

m=4(38)\\m=152

Putting c=38 in Eqn 1;

w=2(38)\\w=76

There are 152 men, 76 women and 38 children.

Keywords: linear equations, substitution method

Learn more about linear equations at:

  • brainly.com/question/3820433
  • brainly.com/question/3852778

#LearnwithBrainly

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