Determine the product of (4.2 × 10–1) ⋅ (5.7 × 10–1). Write your answer in scientific notation. Question 7 options: A) 239.4 × 10–1 B) 2.394 × 10–1 C) 23.94 × 10–1 D) 239.4 × 10–2

Answer: b) 180° rotation & reflection over x-axis

Step-by-step explanation:

Rotation of 180° changes the signs of both x and y.

(x, y) → (-x, -y)

Reflection over the x-axis changes the sign of y.

(-x, -y) → (-x, y)

 (x, y)        (-x, y)  

 (0, 1)   →    (0, 1)

 (1, -1)   →   (-1, -1)

 (5, 3)   →   (-5, 3)

Answer: 20

Step-by-step explanation:

I guess that we want to distribute all the 7 candies between 4 kids

We have 3 options:

first 3, 2, 1 and 1. (the number of candies that each kid gets)

The possible permutations in this case:

if we leave the 3 fixed, the ones do are equal, so the permutations are only given by the change in the kid that gets 2 candies, we have 3 permutations for this.

And for the fixed 3, we have 4 possible places where we can fix it, so the total number of combinations is:

c = 3*4 = 12.

and the second option is (2, 2, 2, 1)

Here the only change is the kid that gets only one candy, we have 4 options in this case:

c = 4.

the third option is (4, 1, 1, 1)

Here the only change is the kid that gets 4 candies, and we have 4 options for this, so we have 4 combinations:

c = 4.

Then the total number of possible combinations is:

C = 12 + 4 + 4 = 20

Answer:

3n>15

Step-by-step explanation:

So basically, this three times a number, 3n, is greater than 15. So, this is 3n>15.

The answer is option A

Step-by-step explanation:

Thirteen less than a number is written as

n - 13

Equate it to 42

We have

n - 13 = 42

Hope this helps you

Answer:

120 m²

Step-by-step explanation:

We khow that the area of a triangle is the product of the lenght and the wight

let x be the width

so the lenght is 15

Answer:

  120 square meters

Step-by-step explanation:

The missing leg of the right triangle is found from the Pythagorean theorem:

  diagonal² = length² + width²

  length² = diagonal² -width²

  length = √(17² -8²) = √(289 -64) = √225 = 15

So, the rectangle is 8 m by 15 m and has an area that is ...

  A = LW = (15 m)(8 m) = 120 m²

Answer:

The right Riemann sum is 21.5.

The left Riemann sum is 29.5.

Step-by-step explanation:

The right Riemann sum (also known as the right endpoint approximation) uses the right endpoints of a sub-interval:

[tex]\int_{a}^{b}f(x)dx\approx\Delta{x}\left(f(x_1)+f(x_2)+f(x_3)+...+f(x_{n-1})+f(x_{n})\right)[/tex], where [tex]\Delta{x}=\frac{b-a}{n}[/tex].

To find the Riemann sum for [tex]\int_{0}^{2}\left(2 x^{2} - 12 x + 22\right)\ dx[/tex] with 4 rectangles, using right endpoints you must:

We have that a = 0, b = 2, n = 4. Therefore, [tex]\Delta{x}=\frac{2-0}{4}=\frac{1}{2}[/tex].

Divide the interval [0,2] into n = 4 sub-intervals of length [tex]\Delta{x}=\frac{1}{2}[/tex]:

[tex]\left[0, \frac{1}{2}\right], \left[\frac{1}{2}, 1\right], \left[1, \frac{3}{2}\right], \left[\frac{3}{2}, 2\right][/tex]

Now, we just evaluate the function at the right endpoints:

[tex]f\left(x_{1}\right)=f\left(\frac{1}{2}\right)=\frac{33}{2}=16.5\\\\f\left(x_{2}\right)=f\left(1\right)=12\\\\f\left(x_{3}\right)=f\left(\frac{3}{2}\right)=\frac{17}{2}=8.5\\\\f\left(x_{4}\right)=f(b)=f\left(2\right)=6[/tex]

Finally, just sum up the above values and multiply by [tex]\Delta{x}=\frac{1}{2}[/tex]:

[tex]\frac{1}{2}(16.5+12+8.5+6)=21.5[/tex]

The left Riemann sum (also known as the left endpoint approximation) uses the left endpoints of a sub-interval:

[tex]\int_{a}^{b}f(x)dx\approx\Delta{x}\left(f(x_0)+f(x_1)+2f(x_2)+...+f(x_{n-2})+f(x_{n-1})\right)[/tex], where [tex]\Delta{x}=\frac{b-a}{n}[/tex].

To find the Riemann sum for [tex]\int_{0}^{2}\left(2 x^{2} - 12 x + 22\right)\ dx[/tex] with 4 rectangles, using left endpoints you must:

We have that a = 0, b = 2, n = 4. Therefore, [tex]\Delta{x}=\frac{2-0}{4}=\frac{1}{2}[/tex].

Divide the interval [0,2] into n = 4 sub-intervals of length [tex]\Delta{x}=\frac{1}{2}[/tex]:

[tex]\left[0, \frac{1}{2}\right], \left[\frac{1}{2}, 1\right], \left[1, \frac{3}{2}\right], \left[\frac{3}{2}, 2\right][/tex]

Now, we just evaluate the function at the left endpoints:

[tex]f\left(x_{0}\right)=f(a)=f\left(0\right)=22\\\\f\left(x_{1}\right)=f\left(\frac{1}{2}\right)=\frac{33}{2}=16.5\\\\f\left(x_{2}\right)=f\left(1\\\right)=12\\\\f\left(x_{3}\right)=f\left(\frac{3}{2}\right)=\frac{17}{2}=8.5[/tex]

Finally, just sum up the above values and multiply by [tex]\Delta{x}=\frac{1}{2}[/tex]:

[tex]\frac{1}{2}(22+16.5+12+8.5)=29.5[/tex]

Answer:

Step-by-step explanation:

Hi there! Hopefully this helps!

------------------------------------------------------------------------------------------------

2 + 2 = 4.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You can simply find this answer by getting two of your fingers on your left hand, getting two MORE fingers of your right hand, and counting them. You will end up with 4.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You could multiply 2 two times, like this:

2 x 2 = 4.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You could split the numbers into parts and add them back together, like this:

2 = 1 + 1.

           +

2 = 1 + 1.

           =

1 + 1 + 1 + 1 = 4.

Answer:

4

Step-by-step explanation:

problem is if you dont have a fingers... you cant physically count 2 + 2

anyway... just add them using your brain = 2 + 2 makes 4

Answer:

$288

Step-by-step explanation:

10% of 240 is 240 / 10 = 24

24 X 2 = 48

240 + 48 = $288

Answer:

$288 ....brainliest appreciated pls

Step-by-step explanation:

20/100 × 240 = 48dollars

so...the selling price becomes 240+48 = $288

Answer:

a. Neither

b. Null hypothesis

c. Neither

d. Alternative hypothesis

Step-by-step explanation:

This hypothesis test wants to test the claim that, in households with a minimum-wage worker, mean household debt increases following a hike in the minimum wage.

Then, the alternative hypothesis, that reflects the claim, will state that the mean household debt significantly increases (under the previous descriptions).

The null hypothesis will state the opposite: that mean household debt does not signficantly increases in that conditions (it stays the same or decreases).

a. In households with a minimum-wage worker, mean household debt decreases following a hike in the minimum wage.  NEITHER.

b. In households with a minimum-wage worker, mean household debt decreases or stays the same following a hike in the minimum wage. NULL HYPOTHESIS.

c. In households with a minimum-wage worker, mean household debt is unaffected by a hike in the minimum wage.  NEITHER.

d. In households with a minimum-wage worker, mean household debt increases following a hike in the minimum wage. ALTERNATIVE HYPOTHESIS.

Answer:

2.5

Step-by-step explanation:

The integral of a function is the area under the curve.

Graph |9x−3|.  The result is two lines.  The areas under these lines are triangles.  The first triangle has a base of ⅓, and a height of 3.  The second triangle has a base of ⅔, and a height of 6.

The total area is therefore:

A = ½ (⅓) (3) + ½ (⅔) (6)

A = ½ + 2

A = 2.5

Answer:y=3/2x-3

Step-by-step explanation: the slope of the graph is (y2-y1)/(x2-x1)

If we take points (0,-3) (2,0) the slope would be (0--3)/(2-0) = 3/2

And the y-intercept of the slope is -3

Hey there! :)

Answer:

≈ $41330

Step-by-step explanation:

Begin by finding the area of the racetrack by subtracting the area of the smaller circle from the larger one.

Calculate the areas of the circles using: A = πr²

Larger circle:

A = π145²

A = 21025π = 66018.5 ft²

Smaller circle:

A = π80²

A = 6400π = 20096 ft²

Subtract the smaller from the larger of the areas:

66018.5 - 20096 = 45922.5 ft²

Divide this by 100 to solve for the amount of asphalt needed:

45922.5 / 100 = 459.225.

Since asphalt costs $90 dollars per 100 ft², then:

459.225 · 90 = $ 41330.25 ≈ $41330 rounded.

Answer:

a. annual income = $31,200

b. Social Security tax  = $1,934.40

c. Medicare =  $452.40

Step-by-step explanation:

40 hours in a week

52 weeks in a year

Tom makes $15 / hour

In a year, the

a. annual income = 15*40*52 = 31200

b. Social Security tax = 31200 * 0.062 = 1934.40

c. Medicare = 31200 * 0.0145 = 452.40

Answer:

Step-by-step explanation:

The domain is {-1, 2} (the domain has only two values).

The range is {-4, -3, 2} (the range contains three values)

Answer:

0.14% probability of a person guessing the right​ combination

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

The order in which the numbers are selected is important. For example, 1,3,2 is a different combination than 3,1,2. So we use the permutations formula to solve this question.

Permutations formula:

The number of possible permutations of x elements from a set of n elements is given by the following formula:

[tex]P_{(n,x)} = \frac{n!}{(n-x)!}[/tex]

Desired outcomes:

One right combination, so [tex]P = 1[/tex]

Total outcomes:

10 numbers from a set of 3. So

[tex]P_{(10,3)} = \frac{10!}{(10-3)!} = 720[/tex]

What is the probability of a person guessing the right​ combination?

[tex]p = \frac{D}{T} = \frac{1}{720} = 0.0014[/tex]

0.14% probability of a person guessing the right​ combination

Answer:

  1

Step-by-step explanation:

The lateral area of a cylinder is ...

  LA = 2πrh

The total area is that added to the areas of the two circular bases:

  A = 2πr² +2πrh

We want the ratio of these to be 1/2:

  LA/A = (2πrh)/(2πr² +2πrh) = h/(r+h) = 1/2 . . . . cancel factors of 2πr

Multiplying by 2(r+h) gives ...

  2h = r+h

  h = r . . . . . subtract h

So, the desired ratio is ...

  h/r = h/h = 1

The ratio between height and radius is 1.

Answer:  [tex]\bold{\dfrac{b_1}{b_2}=\dfrac{3}{2}}[/tex]

Step-by-step explanation:

Inversely proportional means a x b = k   --> b = k/a

Given that a₁ = 2   --> b₁ = k/2

Given that a₂ = 3   -->  b₂ = k/3

[tex]\dfrac{b_1}{b_2}=\dfrac{\frac{k}{2}}{\frac{k}{3}}=\large\boxed{\dfrac{3}{2}}[/tex]

Answer:

(a) matched pair design

(b) n = 30

(c) Reject the null hypothesis.

Step-by-step explanation:

The complete question is:

A researcher records the amount of time (in minutes) that parent child pairs spend on social networking sites to test whether they show any generational differences. From the following findings in APA format, interpret these results by stating the research design used (repeated measures or matched pairs), the sample size, the decision, and the effect size. Parents spend significantly less time on social networking sites compared their children (MD = -42 minutes),t(29)=4.021,p<.05,d=0.49.(a) What research design was used? (Repeated measures or matched pairs?)(b) What is the sample size? (n = ?)(c) What is the decision? (Retain or reject the null?)

Solution:

(a)

It s provided that the researcher records the amount of time (in minutes) that parent-child pairs spend on social networking sites.

This implies that the data collected is in the form of paired data.

Thus, the research design that was used was matched pair design.

(b)

Consider the t-statistics provided:

t (29) = 4.021

The number 29 in the bracket is the degrees of freedom.

The degrees of freedom for a matched pair design is,

df = n - 1

Compute the value of n as follows:

df = n - 1

29 = n - 1

n = 29 + 1

n = 30

Thus, the sample size is n = 30.

(c)

The p-value of the test is:

p < 0.05

The p-value of the test is less than the 5% significance level.

This implies that the null hypothesis will be rejected at 5% significance level.

Answer:

D. The graph of g(x) is shifted 2 units down

Step-by-step explanation:

Since we are modifying b in f(x) = mx + b, we are dealing with vertical movement up and down. Since it is -2, we are moving down 2.

Answer:  k = -9

Step-by-step explanation:

kx² - 12x - 4 = 0

In order to have exactly one solution, it must be a perfect square.

Assume k is negative and factor out a negative 1.

-1(kx² + 12x + 4) = 0

[tex]\bigg(\sqrt{kx^2}+\sqrt4\bigg)^2=0\\\\[/tex]

The middle term = 12x [tex]= 2(\sqrt{kx^2})(\sqrt4)[/tex]

                               12x = 4x√k

                                3   = √k

                                9 = k

-1(9x² + 12x + 4) = 0

-9x² - 12x - 4 = 0

k=-9

Answer:

a) [tex]\mathbf{\dfrac{dx}{dt} = 30 - 0.015 x}[/tex]

b) [tex]\mathbf{x = 2000 - 2000e^{-0.015t}}[/tex]

c)  the  steady state mass of the drug is 2000 mg

d) t ≅ 153.51  minutes

Step-by-step explanation:

From the given information;

At time t= 0

an intravenous line is inserted into a vein (into the tank) that carries a drug solution with a concentration of 500

The inflow rate is 0.06 L/min.

Assume the drug is quickly mixed thoroughly in the blood and that the volume of blood remains constant.

The objective of the question is to calculate the following :

a) Write an initial value problem that models the mass of the drug in the blood for t ≥ 0.

From above information given :

[tex]Rate _{(in)}= 500 \ mg/L \times 0.06 \ L/min = 30 mg/min[/tex]

[tex]Rate _{(out)}=\dfrac{x}{4} \ mg/L \times 0.06 \ L/min = 0.015x \ mg/min[/tex]

Therefore;

[tex]\dfrac{dx}{dt} = Rate_{(in)} - Rate_{(out)}[/tex]

with respect to  x(0) = 0

[tex]\mathbf{\dfrac{dx}{dt} = 30 - 0.015 x}[/tex]

b) Solve the initial value problem and graph both the mass of the drug and the concentration of the drug.

[tex]\dfrac{dx}{dt} = -0.015(x - 2000)[/tex]

[tex]\dfrac{dx}{(x - 2000)} = -0.015 \times dt[/tex]

By Using Integration Method:

[tex]ln(x - 2000) = -0.015t + C[/tex]

[tex]x -2000 = Ce^{(-0.015t)[/tex]

[tex]x = 2000 + Ce^{(-0.015t)}[/tex]

However; if x(0) = 0 ;

Then

C = -2000

Therefore

[tex]\mathbf{x = 2000 - 2000e^{-0.015t}}[/tex]

c) What is the steady-state mass of the drug in the blood?

the steady-state mass of the drug in the blood when t = infinity

[tex]\mathbf{x = 2000 - 2000e^{-0.015 \times \infty }}[/tex]

x = 2000 - 0

x = 2000

Thus; the  steady state mass of the drug is 2000 mg

d) After how many minutes does the drug mass reach 90% of its stead-state level?

After 90% of its steady state level; the mas of the drug is 90% × 2000

= 0.9 × 2000

= 1800

Hence;

[tex]\mathbf{1800 = 2000 - 2000e^{(-0.015t)}}[/tex]

[tex]0.1 = e^{(-0.015t)[/tex]

[tex]ln(0.1) = -0.015t[/tex]

[tex]t = -\dfrac{In(0.1)}{0.015}[/tex]

t = 153.5056729

t ≅ 153.51  minutes

Answer:

24 oz costs $3.75

The rice cost per oz is $0.16

Step-by-step explanation:

Step 1: Set up proportion

16/2.5 = 24/x

Step 2: Cross multiply

16x = 24(2.5)

Step 3: Solve

16x = 60

x = 15/4 or 3.75

Answer:

4/7

Step-by-step explanation:

5+2=7

7 children

4 boys Out of 7 children

Answer:1/7

Step-by-step explanation:

Khan academy

Answer: D  a rotation, then a dilation

Step-by-step explanation:

A triangle is said to be congruent when all angles are equal to each other and and has the same side.

it is similar  when the two angles correspond with each other and has different sides.

so for a triangle to be different in side only a dilation has to be apply to it. Performing a rotation,reflection, and translation doesn't change the size of the shape it  changes the position of the shape.  

A rotation, then a dilation will create a pair of similar, not congruent triangles.

Two triangles are said to be congruent if they have the same shape and their corresponding sides are congruent. Hence all the three sides and three angles are congruent.

Rotation, translation and reflection are rigid transformation and would produce a congruent shape while dilation produces a similar and not congruent shape.

A rotation, then a dilation will create a pair of similar, not congruent triangles.

Find out more on Congruent triangles at: https://brainly.com/question/1675117

Complete Question

Jessica is organizing a guided tour of the rain forest. The average profit per person that the touring company makes is given by the rational expression 18x+35/x, where x is the number of people going on the tour. What does the denominator of this rational expression represents?

Answer:

Number of people going on the tour

Step-by-step explanation:

Given that the average profit per person  [tex]=\dfrac{18x+35}{x}[/tex]

[tex]\text{Average}=\dfrac{\text{Sum of Total Items}}{\text{Number of Items}}[/tex]

Therefore:

[tex]\text{Average Profit}=\dfrac{(18x+35)\text{ profit}}{x\text{ persons}}[/tex]

The denominator, x represents the number of people going on the tour.

Answer:

btw 35/x represents epresents a fixed cost, like a cover charge for the tour, that is not affected by the number of people attending the tour. So, the quotient 35/x represents the profit that the tour company makes from the cover charge per person.

Step-by-step explanation:

PLATO

Answer:

Option D

Step-by-step explanation:

x is given to be 4 in this case, so all we would have to is plug it into the following function -

[tex]f ( x ) = \left \{ {{x - 2, x < 4 } \atop {x + 2, x \geq 4 }} \right[/tex]

Through substitution, you would receive the following function -

[tex]f ( x ) = \left \{ {{2, 4 < 4 } \atop 6, 4 \geq 4 }} \right[/tex]

Now the graph proves that this function is closer to 4, and thus proves that the y - coordinate is about 2 at the same time. However, the graph is cut off, so the limit doesn't exists.

Answer:

  4.5

Step-by-step explanation:

The graph of y = e^x shows the value of e^1.5 to be about 4.5.

Answer:

19.2 feet square

Step-by-step explanation:

We khow that the area of an octagon is :

A= 1/2 * h * P where h is the apothem and p the perimeter