What is the solution of the equation −x2 − 2x = 5?

9514 1404 393

Answer:

  (6,2)

Step-by-step explanation:

As is often the case with multiple-choice problems, you don't actually need to know the detailed working. You just need to know what the answer looks like.

When point X is dilated by a factor of 2 with point Z as the center of dilation, it will move to a location twice as far from Z. You can tell by looking at the graph that X' will be in the first quadrant, above and to the right of the location of X. The only sensible answer choice is ...

  X' = (6, 2)

_____

Additional comment

X is a distance of X-Z = (4, 0) -(2, -2) = (2, 2) from Z Doubling that will put the image point a distance of 2(2, 2) = (4, 4) from Z. When this is added to Z, we find ...

  X' = Z + (4, 4) = (2+4, -2+4) = (6, 2)

Answer:

The 98% confidence interval for the population mean is between 21 and 23.8 years.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.98}{2} = 0.01[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.01 = 0.99[/tex], so Z = 2.327.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 2.327\frac{4.2}{\sqrt{49}} = 1.4[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 22.4 - 1.4 = 21 years.

The upper end of the interval is the sample mean added to M. So it is 22.4 + 1.4 = 23.8 years.

The 98% confidence interval for the population mean is between 21 and 23.8 years.

9514 1404 393

Answer:

  11.6 cm

Step-by-step explanation:

As the page title tells you, the Pythagorean theorem must be applied more than once. As you know, it tells you the square of the hypotenuse is the sum of the squares of the two sides.

  AD² = ED² +EA²

  EA² = AD²-ED² = 7² -6² = 13

  EA = √13 ≈ 3.606

__

  CD² = ED² +EC²

  EC² = CD² -ED² = 10² -6² = 64

  EC = √64 = 8

__

The length of the horizontal diagonal is ...

  AC = EA +EC = 3.6 +8 = 11.6 . . . cm

Answer:

C. A = 40.4 , B = 49.6 , c = 23

Step-by-step explanation:

First, we need to get the c using the pythagoras theorem;

c² = a²+b²

c² = 14.9²+17.5²

c²  = 222.01 + 306.25

c² = 528.26

c = 22.98

c ≈ 23

Using the sin rule;

a/Sin<A  = c/sin<C

14.9/sin<A = 23/sin90

14.9/sin<A = 23

sin<A = 14.9/23

sin <A = 0.6478

<A = arcsin(0.6478)

<A = 40.4degrees

Also, <A + <B + <C = 180

40.4 + <B + 90 = 180

<B = 180 - 130.4

<B = 49.6degrees

Step-by-step explanation:

I cannot draw a diagram here.

but I can explain what to do in general.

the shortest distance from a point to a line is always via a connecting line that is perpendicular to the given line and his through the given point.

and then the distance from the given point to the intersection point is calculated.

every line is defined in the form like

y = ax + b

where a is the slope of the line, and b is the intersection point on the y-axis (the offset from point 0).

the slope of a line is the ratio y/x defining how many units y changes when x changes a certain amount of units.

in our example,

y = 5x - 10

5 (or rather 5/1) is the slope of the line.

it means that y grows by 5 units every time x grows by 1 unit.

a perpendicular line (cuts the original line with a 90 degree angle) has a related slope : it reverts x and y and flips the sign :

5/1 turns into -1/5

that means at the perpendicular line whenever x grows by 5 units, y goes down by 1 unit.

so, the first approach for the perpendicular line is

y = -1/5 x + b

to get b we use the given point (6, 5) that has to be in the perpendicular line.

5 = -1/5 × 6 + b

25/5 = -6/5 + b

31/5 = b

=> y = -1/5 x + 31/5

the intersecting point is now where both lines are equal

5x - 10 = -1/5 x + 31/5

25x - 50 = -x + 31

26x = 81

x = 81/26

y = 5×(81/26) - 10 = 405/26 - 260/26 = 145/26

the distance of the given point (6, 5) to the line intersection point (81/26, 145/26) is the calculated as

distance² = (6 - 81/26)² + (5 - 145/26)²

distance = sqrt((6-81/26)² + (5-145/26)²)

since the result was not requested here, I save us the calculation.

Answer:

2/39

Step-by-step explanation:

You will end up with 12/234

You can simplify it by 6

And then you get 2/39

Answer:

2240

Step-by-step explanation:

4(5)(7)(7+9)

=2240

Answer:

x = 2240

Step-by-step explanation:

x= 4ab(b+9)

x= 4(5)(7)(7+9)

x= 4(35)(16)

x= 4(560)

x= 2240

Answer:

10,13,14,20,30................

Area = length x width

Area = 21 square cm

Width = x

Length = 3x + 2

21 = 3x+ 2 * x

21 = 3x ^2 + 2x

Subtract 21 from both sides:

3x^2 + 2x -21 = 0

Use the quadratic formula to solve for x:

-2 +/- sqrt(2^2-4*3(-21))/(2*3)

X = 7/3 and -3

A dimension can’t be a negative value so x needs to be 7/3

Width = x = 7/3 = 2 1/3 cm

Length = 3(7/3) + 2 = 9 cm

Check: 9 x 2 1/3 = 21

Dimensions: width 2 1/3 cm length 9 cm

Answer:

The dimensions of the rectangle are 7 by 3 centimeters.

Step-by-step explanation:

We are given that the length of a rectangle is two centimeters less than three times its width. In other words:

[tex]\displaystyle \ell = 3w-2[/tex]

Given that the area of the rectangle is 21 square centimeters, we want to determine the dimensions of the rectangle.

Recall that the area of a rectangle is given by:

[tex]A= w\ell[/tex]

Substitute:

[tex](21)=w(3w-2)[/tex]

Solve foro the width. Distribute:

[tex]3w^2-2w=21[/tex]

Isolate the equation:

[tex]3w^2-2w-21=0[/tex]

Factor. Find two numbers that multiply to 3(-21) = -63 and add to -2.

-9 and 7 suffice. Hence:

[tex]3w^2-9w+7w-21=0 \\ \\ 3w(w-3)+7(w-3) = 0 \\ \\ (3w+7)(w-3)=0[/tex]

Zero Product Property:

[tex]3w+7=0\text{ or } w-3=0[/tex]

Solve for each case. Hence:

[tex]\displaystyle w = -\frac{7}{3}\text{ or } w=3[/tex]

Since width cannot be negative, we can ignore the first solution.

Therefore, our width is three centimeters.

And since the length is two less than three times the width, the length is:

[tex]\ell = 3(3) - 2 = 7[/tex]

The dimensions of the rectangle are 7 by 3 centimeters.

Answer:

Answer:     2x^2+11x+15      Coefficient of x is 11 and coefficient of x^2 is 2.

Step-by-step explanation:

(x+3)×(2x+5)=?

           Use FOIL Method                      Foil stands for First Outer Inner Last

Step 1:      (x×2x)        =2x^2                Multiply First Terms together  (x and 2x)

Step 2:     (x×5)         =5x           Multiply Outer terms together (x and 5)

Step 3:    (3×2x)        =6x           Multiply Inner terms together (3 and 2x)

Step 4:     (3×5)         =15            Multiply Last terms together (3 and 5)

2x^2+5x+6x+15             Combine Like Terms

Answer:     2x^2+11x+15

Answer:

747 samples

Step-by-step explanation:

Given:

Standard deviation = √125.44 = 11.2

Zcritical = 85℅

Margin of error, E = 0.59

The sample size, n required cnanbe obtained using the relation :

n = [(Zα/2 * σ) / E]²

Zcritical at 85% = 1.44

n = [(1.44 * 11.2) / 0.59]²

n = (16.128 / 0.59)²

n = 747.23

n = 747 samples

Answer:

bdFd574)466&!'!9+/"(&$4+√®=™]

Answer:

111.1111... lbs

x -.1x = 100

.9x = 100

x = 100/.9 = 111.1111

Step-by-step explanation:

Answer:

$836.8

Step-by-step explanation:

Average price = mean = $965

Standard deviation, = $100

Given that distribution is approximately normal ;

The least expensive 10% of the laptops :

We Obtain the Zscore that corresponds to P(Z ≤ 0.1) ; this means the least 10% of the laptops ;

From, a normal probability distribution table ;

P(Z ≤ 0.1) = - 1.282

We substitute this into the Zscore formula :

Zscore = (x - mean ) / standard deviation

x = price

-1.282 = (x - 965) / 100

-128.2 = (x - 965)

x = - 128.2 + 965

x = $836.8

Hence, price is $836.8

Answer:

the answer to this question is 1

Step-by-step explanation:

the reason to that is because when the line goes over 2 and -2.

Answer:

first part is decreasing and increasing

second part is 3 and 5

Step-by-step explanation:

edg 2021

Answer:

Type I error and Type II error

Explanation:

Type I and Type II errors are statistical errors made in hypothesis testing where an accepted hypothesis is actually the false hypothesis and the other true.

Type I error occurs when the chosen hypothesis is the alternative hypothesis which is false since the null hypothesis is true. We reject the null hypothesis which is actually true.

Type II error occurs when we accept or fail to reject the null hypothesis which is false and reject the alternative hypothesis which is true.

The probability of making a Type I error is represented by your alpha level (α)(we reject when below p-value)

The probability of a type-II error is represented by β which is beta.

Answer:

Step-by-step explanation:

y+5=0

y=-5

it is a line down 5 units parallel to x-axis.

you can take infinie points say (1,-5),(5,-5) ,(7,-5) etc.

Answer:

y = - 5

Step-by-step explanation:

In two dimensions, this is a line parallel to the x - axis. You can also think of it as a locus, the infinite set of points fulfilling  (,− 5)  — any real value of x, but y has to be -5.

Extending it to three dimensions, it is a plane parallel to the x-axis and also to the z-axis, or the locus  (,− 5, ).

Answer:

66

Step-by-step explanation:

let's use x to represent the unknown number

1/2x is 5 more than 6:

↓

1/2x=5+6

solve to find x

1/2x=11

x=22

next, it asks us what is the value of the number when the number is tripled

since we already found what x is equal to, we can multiply that by 3 to figure out its value when it's tripled

3(22)=66

Using mathematical equation to model the scenario, the value of the number when tripled is 66

Let the number = n

0.5n = 5 + 6

0.5n = 11

Divide both sides by 0.5

n = 22

When n is tripled :

n = 22 × 3

n = 66

Hence, the value of the number when tripled is 66

Learn more : https://brainly.com/question/25480062

Answer:-16

Step-by-step explanation:

Answer:

[tex]2x {}^{3} + {8x}^{2} - 6x - 31 + \frac{ - 128}{x - 4} [/tex]

Place the coefficients in the right place.

Answered by GAUTHMATH

Answer: TRUE

Step-by-step explanation:

An arithmetic sequence is a sequence in which the difference between each term (number) is a constant.

Given the sequence is {3, -6, -15, -24}

3 - (-6) = 9

-6 - (-15) = 9

-15 - (-24) = 9

As we can see from above, the difference between the given terms is all 9. Therefore, it is indeed an arithmetic sequence.

Hope this helps!! :)

Please let me know if you have any questions

Answer:

true

Step-by-step explanation:

By definition of conditional probability,

P(X ≤ 0.5 | X ≤ 1) = P((X ≤ 0.5) and (X ≤ 1)) / P(X ≤ 1)

but if X ≤ 0.5, then it's automatic that X ≤ 1, so

P(X ≤ 0.5 | X ≤ 1) = P(X ≤ 0.5) / P(X ≤ 1)

Given the PDF of X,

[tex]f_X(x) = \begin{cases}2e^{-2x}&\text{if }x\ge0\\0&\text{otherwise}\end{cases}[/tex]

the CDF would be

[tex]P(X\le x) = F_X(x) = \displaystyle\int_{-\infty}^x f_X(t)\,\mathrm dt[/tex]

[tex]F_X(x) = \begin{cases}0&\text{if }x<0\\1-e^{-2x}&\text{if }x\ge0\end{cases}[/tex]

So we have

P(X ≤ 0.5 | X ≤ 1) = (1 - exp(-2 × 0.5)) / (1 - exp(-2 × 1))

… = (1 - exp(-1)) / (1 - exp(-2))

… = (1 - 1/e) / (1 - 1/e ²)

… = (e ² - e) / (e ² - 1)

… = e / (e + 1) ≈ 0.7312

Answer:

26 miles per gallon

Step-by-step explanation:

Take the miles and divide by the gallons

455 miles / 17.5 gallons

26 miles per gallon

Answer:

Solution given:

f(x)=ax^4-bx^2+x+5 and

f(-3)=2

f(-3)=a(-3)^4-b(-3)^2+(-3)+5

2=81a-9b-3+5

2=81a-9b+2

subtracting both side by 2 and adding 9b

2-2+9b=81a-9b+9b+2-2

9b=81a

now

f(3)=a(3)^(4)-b(3)^(2)+3+5

f(3)=81a-9b+8

substituting value of 81a

f(3)=9b-9b+8

f(3)=8

Answer:

I think the area is 60 but i couldn't figure out the perimeter, sorry.

Step-by-step explanation:

Answer:

perimeter = 36 m

area = 60 m²

Step-by-step explanation:

there is some missing information. for example about the types of the shapes. e.g. if the triangle on the top is an isosceles triangle (2 equal sides). or if the rectangle at the bottom is actually a square with 6 m on all sides. in order to make the sloped side of the top triangle a round, whole number, i assume that the bottom part is a square.

so, the area of this combined shape is the area of the bottom square plus the area of the top triangle.

area square As = 6×6 = 36 m²

so, one side of the triangle is also 6 m, the other is 14-6 = 8 m.

the area of such a right-angled triangle is half of the full rectangle of 6×8.

area triangle At = 6×8/2 = 48/2 = 24 m²

total area = As + At = 36 + 24 = 60 m²

the perimeter of the total shape is the sum of all sides.

so, 14, 6, 6 and ... the baseline/ Hypotenuse of the top triangle.

for that r need the mentioned Pythagoras :

c² = a² + b²

where a and b are the sides, and c is the Hypotenuse (the side opposite of the 90 degree angle).

so, in our case of an isosceles triangle with a 90 degree angle :

c² = 8² + 6² = 64 + 36 = 100

c = 10 m

so, the perimeter is

14+6+6+10 = 36 m

Answer:

The y intercept is 1

Step-by-step explanation:

The slope intercept form of a line is

y = mx+b  where m is the slope and b is the y intercept

y = 2x+b

Substitute the point into the equation and solve for y

3 = 2(1)+b

3 =2+b

1 = b

The y intercept is 1