All categories

3 years ago

What is the value of x2+9x+20 when x could be -5, -3 or -6

Mathematics

1 answer:

ANTONII [103]3 years ago

3 0

Answer:

Step-by-step explanation:

You should use a ^ to indicate an exponent. x^2 is the same as x².

x² + 9x + 20

Replace the x with (-5).

(-5)² + 9(-5) + 20 = 25-45+20 = 0

Then do the same with x = (-3):

(-3)² + 9(-3) + 20 = 9 - 27 + 20 = 2

You can do x = (-6)

You might be interested in

Help me? shhhhh.....its for a test

Lena [83]

Answer:

1/5

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

Find the difference quotient and simplify your answer. f(x) = 7x − x2, f(7 + h) − f(7) h , h ≠ 0

uranmaximum [27]

Whatever is inside of the ( ), simply plug that digit into the x-values for f(x)
So: f(x) = 7x - x^2, and f(7+h) - f(7)
= [7(7+h) - (7+h)^2] - [7(7) - (7)^2]
= [49+7h - 49+14h+h^2] - [49-49]
= 49-49 + 7h+14h + h^2 = h^2 + 21h =
h (h+21), h (h+21) = 0
h=0... But it stated h cannot = 0
So h+21 = 0, h = -21

4 0

3 years ago

Of 575 broiler chickens purchased from various kinds of food stores in different regions of a country and tested for types of ba

chubhunter [2.5K]

Answer:

a) $0.68 - 2.58 \sqrt{\frac{0.68(1-0.68)}{575}}=0.630$

$0.68 + 2.58 \sqrt{\frac{0.68(1-0.68)}{575}}=0.730$

And the 99% confidence interval would be given (0.630;0.730).

b) We are 99% confident that the true proportion of infected chickens are between 0.63 (63%) and 0.73 (73%)

c) For this case the answer would be No. Since all the required assumptions in order to construct the confidence interval are satisfied, so then the results can be assumed for all the population

Step-by-step explanation:

Previous concepts

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".

$p$ represent the real population proportion of interest

$\hat p =0.68$ represent the estimated proportion

n=575 is the sample size required (variable of interest)

$z$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})$

Part a

The confidence interval would be given by this formula

$\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}$

For the 99% confidence interval the value of $\alpha=1-0.99=0.01$ and $\alpha/2=0.005$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=2.58$

And replacing into the confidence interval formula we got:

$0.68 - 2.58 \sqrt{\frac{0.68(1-0.68)}{575}}=0.630$

$0.68 + 2.58 \sqrt{\frac{0.68(1-0.68)}{575}}=0.730$

And the 99% confidence interval would be given (0.630;0.730).

Part b

We are 99% confident that the true proportion of infected chickens are between 0.63 (63%) and 0.73 (73%)

Part c

For this case the answer would be No. Since all the required assumptions in order to construct the confidence interval are satisfied, so then the results can be assumed for all the population

4 0

3 years ago

The length of a rectangle is 7 inches more than the width. The perimeter is 30 inches. Find the length and the width of the rect

saul85 [17]

Answer:

that's all about my answer

8 0

3 years ago

Points scored in a basketball game vary directly with shots taken. If a player scores 50 points and takes 40

KATRIN_1 [288]

Answer:

She would have scored 75 points.

Step-by-step explanation:

Points scored in a basketball game vary directly with shots taken.

This means that this question can be solved by proportions, using a rule of three.

How many would she have scored if she takes 60 shots?

Using a rule of three:

50 points - 40 shots

x points - 60 shots

Applying cross multiplication:

$40x = 50*60$

Dividing both sides by 40

$x = 50*1.5 = 75$

She would have scored 75 points.

6 0

3 years ago