All categories

1 year ago

Solve the following equation for X. 12r² + 24 = 0

Mathematics

1 answer:

Gelneren [198K]1 year ago

4 0

Answer:

Isolate the variable by dividing each side by factors that don't contain the variable.

r=√−200x

r=−√−200x

You might be interested in

Use completing the square to solve for x in the equation (x+7)(x-9) = 25.

balandron [24]

Answer:

x = 1 ±√89

Step-by-step explanation:

We have the equation:

(x+7)(x-9) = 25

Using distributive property:

x(x-9) + 7(x-9) = 25

x²- 9x + 7x - 63 -25 = 0

x²- 2x - 88 = 0

To complete squares we need to add and subtract 1, as follows:

x²- 2x - 88 +1 -1 = 0

x²- 2x +1 -88 -1 = 0 (this is a perfect square)

(x - 1)² - 89 = 0

Solving for x:

(x - 1)² = 89

x - 1 = ±√89

x = 1 ±√89

6 0

3 years ago

2X+15= -3x how do you work this equation

Sphinxa [80]

Answer: $x=-3$

Add 3x to both sides

$2x+15+3x=-3x+3x\\5x+15=0$

Subtract 15 from both sides

$5x+15-15=0-15\\5x=-15$

Divide both sides by 5

$5x/5=-15/5\\x=-3$

8 0

3 years ago

Read 2 more answers

Assume that a simple random sample has been selected from a normally distributed population. State the hypotheses, find the test

BaLLatris [955]

Solution

Hypotheses:

- The population mean is 132. In order to test the claim that the mean is 132, we should check for if the mean is not 132.

- Thus, the Hypotheses are:

$\begin{gathered} H_0:\mu=132 \\ H_1:\mu\ne132 \end{gathered}$

Test statistic:

- The test statistic has to be a t-statistic because the sample size (n) is less than 30.

- The formula for finding the t-statistic is:

$\begin{gathered} t=\frac{\bar{X}-\mu}{\frac{s}{\sqrt{n}}} \\ \\ where, \\ \bar{X}=\text{ Sample mean} \\ \mu=\text{ Population mean} \\ s=\text{ Standard deviation} \\ n=\text{ Sample size} \end{gathered}$

- Applying the formula, we have:

$\begin{gathered} t=\frac{137-132}{\frac{14.2}{\sqrt{20}}} \\ \\ t=\frac{5}{3.1752} \\ \\ t\approx1.5747 \end{gathered}$

Critical value:

- The critical value t-critical, is gotten by reading off the t-distribution table.

- For this, we need the degrees of freedom (df) which is gotten by the formula:

$\begin{gathered} df=n-1 \\ df=20-1=19 \end{gathered}$

- And then we also use the significance level of 0.1 and the fact that it is a two-tailed test to trace out the t-critical. (Note: significance level of 0.1 implies 10% significance level)

- This is done below:

- The critical value is 1.729

P-value:

- To find the p-value, we simply check the table for where the t-statistic falls.

- The t-statistic given is 1.5747. We simply check which values this falls between in the t-distribution table. It falls between 1.328 and 1.729. We can simply choose a value between 0.1 and 0.05 and multiply the result by 2 since it is a two-tailed test.

- However, we can also use a t-distribution calculator, we have:

- Thus, the p-value is 0.13183

Final Conclusion:

- The p-value is 0.13183, and comparing this to the significance level of 0.1, we can see that 0.13183 is outside the rejection region.

- Thus, the result is not significant and we fail to reject the null hypothesis

7 0

1 year ago

Charlotte works at an electronics store as a salesperson. Charlotte earns a 10% commission on the total dollar amount of all pho

Ymorist [56]

Answer:

I think it's 0.648

Step-by-step explanation:

10% of 4% of 162 = 0.648

5 0

2 years ago

Rebecca has 12 photos she wants to hang side by side on her wall.A. If she only wants to display 8 of the photos, in how many wa

Mariana [72]

If she will choose 8 from 12 photos, the total number of ways she can choose is given by a combination of 12 choose 8, since the order of the photos doesn't matter.

The formula for a combination of n choose p is:

$C(n,p)=\frac{n!}{p!(n-p)!}$

For n = 12 and p = 8, we have:

$C(12,8)=\frac{12!}{8!(12-8)!_{}}=\frac{12\cdot11\cdot10\cdot9\cdot8!}{8!\cdot4!}=\frac{12\cdot11\cdot10\cdot9}{4\cdot3\cdot2}=495$

So there are 495 ways.

If she wants to arrange the 12 photos, the total number of ways is given by the factorial of 12:

$12!=12\cdot11\cdot10\cdot9\cdot8\cdot7\cdot6\cdot5\cdot4\cdot3\cdot2=479001600$

There are 479,001,600 ways.

Since 10 photos already have specific places, we need to calculate the number of ways to arrange the other two photos in the two remaining places.

In this case, there are only 2 ways of organizing the remaining two photos:

Photo 1 first, photo 2 last, or photo 1 last and photo 2 first.

6 0

1 year ago