Please help me solve these questions!!!

For what values of the variables are the following expressions defined? 1. 5y+2 2. 18/y 3. 1/x+7 4. 2b/10−b Example: X>7

Serga [27]

Answer:

1. All real numbers

2. All real numbers except y = 0

3. All real numbers except x = -7

4. All real numbers except b = 10

Step-by-step explanation:

For any function to be defined at a particular value, it should not be approaching to a value $\infty$ or it should not give us the $\frac{0}{0}$ (zero by zero) form when the input is given to the function.

The value of function will depend on the denominator.

Now, let us consider the given functions one by one:

1. 5y+2

Here denominator is 1. So, it can not attain a value $\infty$ or $\frac{0}{0}$ (zero by zero) form

So, for all real numbers, the function is defined.

$2.\ \dfrac{18}{y}$

At y = 0, the value

$At\ y =0, \dfrac{18}{y} \rightarrow \infty$

So, the given function is defined for all real numbers except y = 0

$3.\ \dfrac{1}{x+7}$

Let us consider denominator:

x + 7 can be zero at a value x = -7

$At\ x =-7, \dfrac{1}{x+7} \rightarrow \infty$

So, the given function is defined for all real numbers except x = -7

$4.\ \dfrac{2b}{10-b}$

Let us consider denominator:

10-b can be zero at a value b = 10

$At\ b =10, \dfrac{2b}{10-b} \rightarrow \infty$

So, the given function is defined for all real numbers except b = 10

7 0

3 years ago

An engineer has designed a valve that will regulate water pressure on an automobile engine. The valve was tested on 180180 engin

tiny-mole [99]

Answer:

$z=\frac{4.6-4.8}{\frac{0.9}{\sqrt{180}}}=-2.98$

$p_v =P(Z$

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis,and we have enough evidence to conclude that the true mean is significantly lower thn 4.8 at 10% of signficance.

Step-by-step explanation:

Data given and notation

$\bar X=4.6$ represent the sample mean

$\sigma=0.9$ represent the population standard deviation

$n=180$ sample size

$\mu_o =4.8$ represent the value that we want to test

$\alpha=0.1$ 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 thetrue mean is below the specifications, the system of hypothesis would be:

Null hypothesis: $\mu \geq 4.8$

Alternative hypothesis: $\mu < 4.8$

If we analyze the size for the sample is > 30 and we know the population deviation so 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:

$z=\frac{4.6-4.8}{\frac{0.9}{\sqrt{180}}}=-2.98$

P-value

Since is a one sided test the p value would be:

$p_v =P(Z$

Conclusion

If we compare the p value and the significance level given $\alpha=0.1$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis,and we have enough evidence to conclude that the true mean is significantly lower thn 4.8 at 10% of signficance.

4 0

2 years ago

Plzzzzzzzzz help me whoever gets it right gets brainliest! how many potatoes and how many corrots

DochEvi [55]

The answer is 10 carrots and 5 potatoes.

8 0

3 years ago

A truck travels on the highway at a speed of 72 miles per hour. What is the speed of the truck in feet per second

Dmitry_Shevchenko [17]

The answer is .02 per second

7 0

2 years ago

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Given that ∠A and ∠B are supplementary, Daisy conjectured that ∠A≅∠B .

dexar [7]

When two angles are supplementary, that means that the sum of their individual angles is equal to a straight line, which is 180°. If you add another restriction where the two supplementary angles are equal, then each vale of the angle constitutes half of 180°. Then, that means that ∠A = ∠B = 90°. The answer is C.

3 0

2 years ago

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