Use inverse operation to solve 116=4n

Question 1 (1 point)

olga55 [171]

Answer:

1) $2y^{2}+4y-9$

2) $18x^{5}y^{4}z$

3) $6x^{5}-12x^{4}+9x^{3}$

4) 40

5) $x^{3}-7x^{2}+3x+36$

Step-by-step explanation:

1) Distribute the negative sign that is outside the parentheses and then you must add like terms, as following:

$(y^{2}-3y-5)-(-y^{2}-7y+4)=y^{2}-3y-5+y^{2}+7y-4=2y^{2}+4y-9$

2) According to the Product property of exponents, when you multiply powers with the same base, you must add the exponents. Then:

$(6xy^{3}z)(3x^{2}yx^{2})=18x^{5}y^{4}z$

3) Apply the Distributive property and the Product property of exponents. Then, you obtain:

$-3x^{3}(-2x^{2}+4x-3)=6x^{5}-12x^{4}+9x^{3}$

4) $(4a+5)^{2}$ is a square of a sum, then, by definition you have:

$(a+b)^{2}=a^{2}+2ab+b^{2}$

Then:

$(4a+5)^{2}=(4a)^{2}+2(4a)(5)+5^{2}=16a^{2}+40a+25$

The coefficient of the second term is the number in front of the variable <em>a.</em> Then, the answer is: 40

5) Apply the Distributive property and the Product property of exponents, then, oyou must add the like terms:

$(x-4)(x^{2}-3x-9)=x^{3}-3x^{2}-9x-4x^{2}+12x+36=x^{3}-7x^{2}+3x+36$

6 0

3 years ago

Ricardo purchased a new car with special 1.9% financing. If the cars price was 17,999 and he financed it for years, find his mon

frosja888 [35]

Answer:

the answer is actually $389.71

Step-by-step explanation:

4 0

3 years ago

The following data lists the ages of a random selection of actresses when they won an award in the category of Best Actress, al

Valentin [98]

Answer:

a) $p_v =P(t_{(9)}$

The p value is higher than the significance level given 0.01, so then we can conclude that we FAIL to reject the null hypothesis. And we can say that the true difference for Best Actresses is not significantly lower than the mean for Best Actors at 1% of significance.

b) The 99% confidence interval would be given by (-21.469;2.069)

c) We got the same conclusion as part a, sicne the confidence interval contains the value 0, we FAIL to reject the null hypothesis that the difference between the two

Step-by-step explanation:

Part a

Let put some notation

x=actor's age , y = actress's age

x: 58 41 36 36 34 33 48 37 37 43

y: 26 27 34 26 35 29 23 42 30 34

The system of hypothesis for this case are:

Null hypothesis: $\mu_y- \mu_x \geq 0$

Alternative hypothesis: $\mu_y -\mu_x$

The first step is calculate the difference $d_i=y_i-x_i$ and we obtain this:

d: -32, -14, -2, -10, 1, -4, -25, 5, -7, -9

The second step is calculate the mean difference

$\bar d= \frac{\sum_{i=1}^n d_i}{n}= -9.7$

The third step would be calculate the standard deviation for the differences, and we got:

$s_d =\frac{\sum_{i=1}^n (d_i -\bar d)^2}{n-1} =11.451$

The 4 step is calculate the statistic given by :

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=\frac{-9.7 -0}{\frac{11.451}{\sqrt{10}}}=-2.679$

The next step is calculate the degrees of freedom given by:

$df=n-1=10-1=9$

Now we can calculate the p value, since we have a left tailed test the p value is given by:

$p_v =P(t_{(9)}$

The p value is higher than the significance level given 0.01, so then we can conclude that we FAIL to reject the null hypothesis. And we can say that the true difference for Best Actresses is not significantly lower than the mean for Best Actors at 1% of significance.

Part b

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The confidence interval for the mean is given by the following formula:

$\bar d \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

Since the Confidence is 0.99 or 99%, the value of $\alpha=0.01$ and $\alpha/2 =0.005$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.005,9)".And we see that $t_{\alpha/2}=3.25$

Now we have everything in order to replace into formula (1):

$-9.7-3.25\frac{11.451}{\sqrt{10}}=-21.469$

$-9.7+3.25\frac{11.451}{\sqrt{10}}=2.069$

So on this case the 99% confidence interval would be given by (-21.469;2.069)

Part c

We got the same conclusion as part a, sicne the confidence interval contains the value 0, we FAIL to reject the null hypothesis that the difference between the two means is 0.

8 0

3 years ago

You are skiing down a mountain with a vertical height of 1250 feet. The distance that you ski as you go from the top down to the

noname [10]

Step-by-step explanation:

here is the answer to your question

5 0

3 years ago

Please help. I dont understand

Gennadij [26K]

Answer: try b

Step-by-step explanation:

glad i could help!

8 0

2 years ago