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IgorC [24]
3 years ago
7

Given: y= 2x + 1 and - 4x + y = 9, solve the system by substitution

Mathematics
1 answer:
kicyunya [14]3 years ago
6 0

Answer:

x=-4     y=-7

Step-by-step explanation:

-4x+y=9     get y alone

add 4x both sides

y=4x+9

insert into y=2x+1

2x+1=4x+9

subtract 1 both sides

2x=4x+8

subtract 4x both sides

-2x=8

divide by -2

x=-4

y=2x+1

y=2(-4)+1

y=-8+1

y=-7

check

-4(-4)+(-7)=9

-16+(-7)=9

9=9

x=-4

y=-7

gl

                 

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lisabon 2012 [21]
For step one, it’s Graph A because it’s going through the origin
For step two, the rate of change is -3, you can find the answer by using the rise/run method by going down three and going right once.
For step 3, the dividing method doesn’t work because -1 divided by 2 isn’t 0.
For step four, go to the point (-2,-4) and from that point draw a line up three units. From there draw a line right two units, and you should stop at -1 on the 6-axis

I hope this helped!
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3 years ago
State the amplitude, period, vertical shift, and horizontal shift for: y = 6 sin(40) + 5
FromTheMoon [43]

Answer:

17

Step-by-step explanation:

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2 years ago
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7 0
2 years ago
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Suppose the standard deviation of a normal population is known to be 3, and H0 asserts that the mean is equal to 12. A random sa
blagie [28]

Answer:

z=\frac{12.95-12}{\frac{3}{\sqrt{36}}}=1.9  

p_v =P(z>1.9)=0.0287  

If we compare the p value and the significance level given \alpha=0.05 we see that p_v so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the true mean is higher than 12 at 5% of signficance.  

Step-by-step explanation:

Data given and notation  

\bar X=12.95 represent the sample mean

\sigma=3 represent the population standard deviation for the sample  

n=36 sample size  

\mu_o =12 represent the value that we want to test  

\alpha=0.05 represent the significance level for the hypothesis test.  

z would represent the statistic (variable of interest)  

p_v represent the p value for the test (variable of interest)  

State the null and alternative hypotheses.  

We need to conduct a hypothesis in order to check if the mean is equal to 12, the system of hypothesis would be:  

Null hypothesis:\mu \leq 12  

Alternative hypothesis:\mu > 12  

Since we know the population deviation, is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:  

z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}} (1)  

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".  

Calculate the statistic  

We can replace in formula (1) the info given like this:  

z=\frac{12.95-12}{\frac{3}{\sqrt{36}}}=1.9  

P-value  

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

p_v =P(z>1.9)=0.0287  

Conclusion  

If we compare the p value and the significance level given \alpha=0.05 we see that p_v so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the true mean is higher than 12 at 5% of signficance.  

4 0
3 years ago
Read 2 more answers
What is the area of the rectangle with points of (-5,5) (-1,7) (0,-5) (4,-3)
Gre4nikov [31]

Answer

l =5

w =2

Area of Rectangle= l ×  w

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Diagram is attached to this:    

Step-by-step explanation:

Download pdf
5 0
3 years ago
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