3x + 5y + 7x - 3y<br> Simplify

Solve for the following proportion for v.

ludmilkaskok [199]

Answer:

20/ 11 and if u want it in decimal it's 1.818182

6 0

3 years ago

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Which operation will cancel out division?

emmasim [6.3K]

Answer:

The operation that will cancel out division is multiplication.

Step-by-step explanation:

For example:

$\frac{2+5x}{2} \\$

*in order to solve for x, and get the upper equation without division, you must multiply by the negative reciprocal*

$2*(\frac{2+5x}2} )$

$4+10x\\$

*to get x alone, we must subtract 4 from both sides*

$10x = -4\\\\-4 / 10 = - 2/5$

$x=- 2/5$

8 0

3 years ago

Choose two positive integers a and b, making sure that a<5 and b>80 . The width of a rectangular computer screen is a inch

qwelly [4]

Answer:

Dimensions of the screen are a minimum of 10 inches wide by 8 inches high. The difference between the height and width will be 2 inches

Step-by-step explanation:

$Height = H$

$Width = H + a$

$Area = Height x Width$

$b = H * (H + a)$

$b = H^{2} + aH$

$H^{2} + aH > 80$

$H^{2} + aH - 80 > 0$

a<5 means 'a' can be a = 1, 2, 3, 4

Solving for H for each option of 'a' will give values of 'H' using the quadratic formula below

$H = \frac{-b\±\sqrt{b^{2}-4ac}}{2a}$

As 'a' and 'b' must be positive integers, H and W must be positive integers as well,

$a = 1, H = 8.46, H = -9.46$

$a = 2, H = 8, H = -10$

$a = 3, H = 7.57, H = -10.57$

$a = 4, H = 7.17, H = -11.17$

Based on above possible answers:

$a=2, H=8$

$W = H + a$

$W = 8 + 2$

$W = 10$

Dimensions of the screen are a minimum of 10 inches wide by 8 inches high. The difference between the height and width will be 2 inches

5 0

3 years ago

g A researcher wants to construct a 95% confidence interval for the proportion of children aged 8-10 living in Atlanta who own a

Helga [31]

Answer:

The sample size needed is 2401.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error of the interval is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

Estimate the sample size needed if no estimate of p is available so that the confidence interval will have a margin of error of 0.02.

We have to find n, for which M = 0.02.

There is no estimate of p available, so we use $\pi = 0.5$

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.02 = 1.96\sqrt{\frac{0.5*0.5}{n}}$

$0.02\sqrt{n} = 1.96*0.5$

$\sqrt{n} = \frac{1.96*0.5}{0.02}$

$(\sqrt{n})^{2} = (\frac{1.96*0.5}{0.02})^{2}$

$n = 2401$

The sample size needed is 2401.

7 0

3 years ago

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In which number does the digit 2 have a value that is ten times as great as the value of the digit 2 in the number 135,284?

Valentin [98]

Answer: See explanation

Step-by-step explanation:

You didn't give the options but let me help out.

First and foremost, we should note that the value of the digit 2 in the number 135,284 is 200. Therefore, the value that is ten times as great as the value of the digit 2 in the number 135,284 would be:

= 10 × 200

= 2000

Therefore, the 2 must be in the thousands place. This can be seen in numbers such as:

172748.

6 0

3 years ago

3x + 5y + 7x - 3y Simplify