Can someone please help me with this

What does x equal 7(2x+5)=4x -9 -x <br> PLEASEEEE HELPPPP ME

Gennadij [26K]

Answer: x=-4

Step-by-step explanation:

Given

7(2x+5)=4x-9-x

Expand parenthesis

14x+35=4x-9-x

Combine like terms

14x+35=3x-9

Subtract 35 on both sides

14x+35-35=3x-9-35

14x=3x-44

Subtract 3x on both sides

14x-3x=3x-44-3x

11x=-44

Divide 11 on both sides

11x/11=-44/11

x=-4

Hope this helps!! :)

Please let me know if you have any questions

5 0

3 years ago

Solve |x+2| >5-(x-1)^2 by graphing

Anna35 [415]

Answer:

x

<

−

1

or

x

>

2

Step-by-step explanation:

7 0

3 years ago

Write equations for the horizontal and vertical lines passing through the point , −8−5.

Allisa [31]

Step-by-step explanation:

sorry I don't know about this

3 0

3 years ago

A sample was taken of the salaries of four employees from a large company. the following are their salaries, in thousands of dol

Free_Kalibri [48]

For given sample of salaries of four employees, the variance of their salaries is: 26 thousands of dollars

The formula for the variance is,

$S^2=\frac{\sum (x_i - \bar{x})^2}{n-1}$

where,

$S^2$ = sample variance

$x_i$ = the value of the one observation

$\bar{x}$ = the mean value of all observations

n = the number of observations

For given question,

n = 4

First we find the mean of their salaries.

(33 + 31 + 24 + 36 ) / 4 = 31

So, $\bar{x}=31$

Using the formula for variance ,

$S^2=\frac{(33-31)^2}{4-1}+\frac{(31-31)^2}{4-1}+\frac{(24-31)^2}{4-1}+\frac{(36-31)^2}{4-1}\\\\ S^2=\frac{4}{3} + \frac{0}{3} + \frac{49}{3} + \frac{25}{3} \\\\S^2= \frac{4+49+25}{3}\\\\S^2=\frac{78}{3} \\\\S^2=26$

Therefore, for given sample of salaries of four employees, the variance of their salaries is: 26 thousands of dollars

Learn more about the variance here:

brainly.com/question/13673183

#SPJ4

7 0

2 years ago

An experiment to investigate the survival time in hours of an electronic component consists of placing the parts in a test cell

mixer [17]

Answer:

a) The sample mean is of 49 and the sample standard deviation is of 11.7.

b) The range of the true mean at 90% confidence level is of 9.62 hours.

c) The prediction interval, at a 90% confidence level, of it's failure time is between 39.38 hours and 58.62 hours.

Step-by-step explanation:

Question a:

Sample mean:

$\overline{x} = \frac{34+40+46+49+61+64}{6} = 49$

Sample standard deviation:

$s = sqrt{\frac{(34-49)^2+(40-49)^2+(46-49)^2+(49-49)^2+(61-49)^2+(64-49)^2}{5}} = 11.7$

The sample mean is of 49 and the sample standard deviation is of 11.7.

b)Determine the range of the true mean at 90% confidence level.

We have to find the margin of error of the confidence interval. Since we have the standard deviation for the sample, the t-distribution is used.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 6 - 1 = 5

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 5 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.9}{2} = 0.95$ . So we have T = 2.0.150

The margin of error is:

$M = T\frac{s}{\sqrt{n}}$

In which s is the standard deviation of the sample and n is the size of the sample. So

$M = 2.0150\frac{11.7}{\sqrt{6}} = 9.62$

The range of the true mean at 90% confidence level is of 9.62 hours.

(c)If a seventh sample is tested, what is the prediction interval (90% confidence level) of its failure time.

This is the confidence interval, so:

The lower end of the interval is the sample mean subtracted by M. So it is 49 - 9.62 = 39.38 hours.

The upper end of the interval is the sample mean added to M. So it is 49 + 9.62 = 58.62 hours.

The prediction interval, at a 90% confidence level, of it's failure time is between 39.38 hours and 58.62 hours.

4 0

2 years ago