How do you solve 2x+4=7

Which function has zeros of -8,1, and 3

grin007 [14]

Answer:

A

Step-by-step explanation:

The zeros of a polynomial function are found by factoring in the form

a(x - r1)(x - r2)(x - r3) ... = 0, where each 'r-something' is a root (or solution) and 'a' is the leading coefficient.

Like if we have 3x² - 3x - 6 = 0

Factoring it as 3(x-2)(x + 1) = 0 shows the roots are 2 and -1.

And sine the right side is zero, we can even drop the factor of 3 on the left, and still have an equivalent equation (has same answers).

(x-2)(x + 1) = 0

The reason this works is because each factor in parentheses adds up to zero, creating a factor of zero in what is being multiplied on the left. And we know that if you have a series of factors in a product, and any one of those factors is zero, the whole product must be zero. So what is on the left equals the zero on the right, making the equation true.

4 0

3 years ago

Use a calculator to evaluate cot π/5.

bixtya [17]

Pi divided by five is roughly .63. I say "roughly" because pi is infinitely long so it's impossible to get an exact answer, but a common pi length would be 3.14159.

7 0

4 years ago

To get an estimate of consumer spending over a holiday season in 2009, 436 randomly sampled American adults were surveyed. Their

Tatiana [17]

Answer:

-A 90% confidence interval would be narrower than the 95% confidence interval if we don't need to be as sure about our estimate.

-This confidence interval is not valid since the distribution of spending in the sample data is right skewed.

-The margin of error is $4.4.

-This confidence interval is valid since the sampling distribution of sample mean would be approximately normal with sample size of 436.

-We are 95% confident that the average spending of all American adults over this holiday season is between $80.31 and $89.11.

Step-by-step explanation:

A 90% confidence interval would be narrower than the 95% confidence interval if we don't need to be as sure about our estimate.

TRUE. The 90% confidence is less strict in its probability of having the mean within the interval, so it is narrower than the 95% CI. It relies more in the information given by the sample.

In order to decrease the margin of error of a 95% confidence interval to a third of what is is now, we would need to use a sample 3 times larger.

FALSE. The margin of error is z*σ/(n^0.5). So to reduce it by two thirds, the sample size n needs to be 3^2=9 times larger.

This confidence interval is not valid since the distribution of spending in the sample data is right skewed.

FALSE. There is no information about the skewness in the sample.

The margin of error is $4.4.

TRUE. The margin of error is (89.11-80.31)/2=$4.4.

We are 95% confident that the average spending of these 435 American adults over this holiday season is between $80.31 and $89.11.

FALSE. The CI is related to the populations mean. We are 95% confident that the average spending of the population is between $80.31 and $89.11.

This confidence interval is valid since the sampling distribution of sample mean would be approximately normal with sample size of 436.

TRUE. This happens accordingly to the Central Limit Theorem.

95% of random samples have a sample mean between $80.31 and $89.11.

FALSE. The confidence interval refers to the population mean.

We are 95% confident that the average spending of all American adults over this holiday season is between $80.31 and $89.11.

TRUE. This is the conclusion that is looked for when constructing a confidence interval.

6 0

4 years ago

Thanks for the help !

UkoKoshka [18]

Answer:

Quadrant 4!

Step-by-step explanation:

It isn't quite 2 pi, so it doesn't make it around the circle twice, making it land in quadrant 4

6 0

3 years ago

Read 2 more answers

Please help me with this ................

Alik [6]

Answer:

Step 4 or the final bubble

Step-by-step explanation:

she did not subtract, she added

SO it should be x = -2

6 0

3 years ago