Solve x2 + 8x + 22 = 0 by completing the square.
Question 20 options:

A)

x = –4 + i√ 6 , x = –4 – i√ 6


B)

x = –4 + √ 14 , x = –4 – √ 14


C)

x = –4 + i√ 14 , x = –4 – i√ 14


D)

x = –4 + √ 6 , x = –4 – √ 6

Let X(s) and Y(s) denote the Laplace transforms of x(t) and y(t), respectively. Then taking the transform of both sides of both equations gives

LT[dx/dt + 5x + dy/dt] = LT[1]

==>   s X(s) - x (0) + 5 X(s) + s Y(s) - y (0) = 1/s

==>   s X(s) + 5 X(s) + s Y(s) = 1/s

==>   (s + 5) X(s) + s Y(s) = 1/s

LT[dx/dt - x + dy/dt - y] = LT[exp(t )]

==>   s X(s) - x (0) - X(s) + s Y(s) - y (0) - Y(s) = 1/(s - 1)

==>   s X(s) - X(s) + s Y(s) - Y(s) = 1/(s - 1)

==>   (s - 1) X(s) + (s - 1) Y(s) = 1/(s - 1)

Solve for X(s) and Y(s). Using elimination, you would get

X(s) = (1 - 2s) / (5s (s - 1)²)

Y(s) = (7s - 1) / (5s (s - 1)²)

Now take the inverse transforms of each. Start by getting the partial fraction decompositions:

(1 - 2s) / (5s (s - 1)²) = 1/5 (a/s + b/(s - 1) + c/(s - 1)²)

-2s + 1 = a (s - 1)² + bs (s - 1) + cs

-2s + 1 = (a + b) s ² + (-2a - b + c) s + a

==>   a + b = 0, -2a - b + c = -10, a = 5

==>   a = 1, b = -1, c = -1

==>   X(s) = 1/5 (1/s - 1/(s - 1) - 1/(s - 1)²)

Similarly, you would find

Y(s) = -1/5 (1/s - 1/(s - 1) - 6/(s - 1)²)

Now for the inverse transforms:

LT⁻¹ [1/s] = 1

LT⁻¹ [1/(s - 1)] = exp(t )

LT⁻¹ [1/(s - 1)²] = t exp(t )

Putting everything together, we have

LT⁻¹ [X(s)] = x(t) = 1/5 - 1/5 exp(t ) - 1/5 t exp(t )

and

LT⁻¹ [Y(s)] = y(t) = -1/5 + 1/5 exp(t ) + 6/5 t exp(t )

Answer:

mean ≈ 25.45

Step-by-step explanation:

mean is calculated as

mean = [tex]\frac{sum}{count}[/tex]

We require the sum for both classes

class A

mean = [tex]\frac{sum}{9}[/tex] = 40 ( multiply both sides by 9 )

sum = 9 × 40 = 360

class B

mean = [tex]\frac{sum}{24}[/tex] = 20 ( multiply both sides by 24

sum = 24 × 20 = 480

Total sum for both classes = 360 + 480 = 840 , then mean for both classes is

mean = [tex]\frac{840}{33}[/tex] ≈ 25.45 ( to 2 dec. places )

Answer:

Q2) 29 degree       as unrounded to nearest degree is 28.95 degree

Q3) 69 degree       as unrounded to nearest degree is 68.56 degree

Step-by-step explanation:

QU 2)

When they speak of plane we see ABCD and also see ABC

So we need the length of AB and BC to find the diagonal CA

AB^2 + BC^2 = CA^2

16.4^2 + 9.1^2 = sqrt 351.77

CA^2 = sqrt 351.77 = 18.8 cm

We know CG = 10.4cm

We identify the hypotenuse for ACG triangle

We do trig tan x = opp/adj for CGA angle

Tan x = tan-1 10.4/18.8 = 28.95099521 degree

Tan x = tan-1 18.8/10.4 = 61.04900479 degree

so we know one is much smaller than the other

We also know ACG angle is 90 degree and that angle from ABCD that meets line AG is the smaller angle.

Answer therefore must be 28.95 degree = or 29 degree

QU 3)

we are basically looking for angle where VB meets BC line or AVB meets ABC we have the slant length, so step 1 is find the height by first dividing square base by 2 then finding the height.

= 7.6/2 = 3.8 cm

Then Pythagoras

BV^2  -  1/2 BC =  height

10.4^2  - 3.8^2 = height

Height = sq rt 93.72 =9.68090905 = 9.7cm

Which means  V to midpoint VC = V to midpoint  AB

They are the same and the midpoints are 90 degree angles.

To find the required angle for VB + BCmidpoint or we wont be able to determine the right angle hypotenuse.

We do the same as last question determine the hypotenuse and where the angle sought is is where we use the trig function = adj/hyp

Because if it was the midpoint angle then it would be opp/adj like the question 1  so this time its cos of x.

cos x = adj/hyp = cos-1 (3.8/ 10.4) = 68.5687455

Answer is 68.56 degree

The reason we show the height is so we can check by doing opp/hyp

= sin of x = sin-1 (9.68090905/3.8) = 23.11171135

and 90 -23.11171135 = 66.8882887

= 67 degree

So we go with the first one and assume 9.68 was already simplified to 9.7cm

= sin-1 (3.8/9.7) = 23 degree  90-23 = 67 degree

but when rounded to 10.4cm for slant we get the same

= sin-1 (3.8/10.4)

So we realise here trig functions -1  doesn't work on the same 90 degree angle for both lines that meet such 90 degree angle.

We try the sin-1 (10.4/ 9.68090905) = 68.5687455 = 69 degree

and that where the lines join away from the 90 degree angle we can always find true answer, and see it is a match with the first cos trig function we did.

This proves that cos line 1/line2  = sin line 1/line 2 are the same when the larger number is numerator for sin representing the hypotenuse slant for sin as shown and when the larger of the sides is numerator for cos di

and smallest side acts as denominator for both trig functions.

Answer:

yes

Step-by-step explanation:

3/9  Divide the top and bottom by 3

1/3

5/15 Divide the top and bottom by 5

1/3

They are equal

Answer:

arithmetic

hyj

bhhm

bm.hg

hgjm

hgjgshmih

mhh

jhuu

Answer:

42

Step-by-step explanation:

2,​4,6,10,​16,26,​___

The pattern is adding the previous two numbers to get the next number

2+4 = 6

4+6 = 10

6+10 = 16

10+16 = 26

16+26 =42

Answer:

x = -3  or x = 3  or x = 6

Step-by-step explanation:

x3 – 6x2 – 9x + 54 = 0

There is no common factor to factor out. There are 4 terms. We try factoring by grouping. Factor a common factor out of the first two terms. Factor a common factor out of the last two terms.

x^2(x - 6) - 9(x - 6) = 0

x - 6 is a common factor, so we factor it out.

(x^2 - 9)(x - 6) = 0

x^2 - 9 is the difference of 2 squares, so we factor it.

(x + 3)(x - 3)(x - 6) = 0

x + 3 = 0  or  x - 3 = 0  or x - 6 = 0

x = -3  or x = 3  or x = 6

Answer:

x=6     x=3   x=-3

Step-by-step explanation:

x^3 – 6x^2 – 9x + 54 = 0

Factor by grouping

x^3 – 6x^2     – 9x + 54 = 0

x^2(x-6)    -9(x-6 ) =0

Factor out x-6

(x-6)(x^2 -9) =0

Notice x^2 -9 is the difference of squares

(x-6)(x-3)(x+3) = 0

Using the zero product property

x-6 =0    x-3 =0   x+3 =0

x=6     x=3   x=-3

Answer:

Đối tượng kế toán là sự hình thành và biến động của tài sản mà kế toán phải phản ánh và giám đốc trong quá trình hoạt động của đơn vị được thể hiện ở hai mặt là Tài sản và Nguồn vốn. Tài sản của đơn vị; Sự vận động của tài sản.

Answer:

[tex]269 \frac{1}{4} [/tex]

Step-by-step explanation:

the solution is found above in the diagram.

Answer:

I have to go get my car from the doctor office today

AS IN THE PICTURE...........

Answer:

[tex]d=\sqrt{(x_{2}-x_{1})^{2} +(y_{2}-y_{1})^{2} } \\\\=\sqrt{(4-(-1))^{2}+(7-9)^{2} } \\\\=\sqrt{(5)^{2}+(-2)^{2}} \\\\=\sqrt{25+4} \\\\=\sqrt{29}[/tex]

Answer:

[tex]Given:[/tex] Δ ABC ≈ ΔDEF

[tex]therefor:[/tex] A(ΔABC)/A(ΔDEF)=(BC)²/(EF)²

⇒ 34/A(ΔDEF)=9²/(13.5)²

⇒34/A(ΔDEF)=81/182.25

⇒A(ΔDEF)=34×182.25/81

⇒Area of ΔDEF=76.5 cm²

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

Hope it helps...

Have a great day!!!

Answer:9oooooooooooooooooooooooooooooooooooo

Step-by-step explanation:

Answer:

option b

Step-by-step explanation:

both are rectangles and similar measures  

Yes, because both figures are rectangles and all rectangles are similar

The rectangle EFGH is a result of the dilation of rectangle ABCD

Resizing an item uses a transition called Dilation. Dilation is used to enlarge or contract the items. The result of this transformation is an image with the same shape as the original. However, there is a variation in the shape's size. Dilation transformations ensure that the shape will stay the same and that corresponding angles will be congruent

Given data ,

Let the first rectangle be represented as ABCD

Now , the rectangle is dilated by a scale factor k

And , the transformed rectangle is given by EFGH

where the center of origin is the scale factor of dilation

Now , the ratios of the sides of the rectangles will be similar

So , the rectangles ABCD and EFGH are similar

Hence , the dilated rectangle is EFGH

To learn more about dilation click :

https://brainly.com/question/13176891

#SPJ7

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Explanation:

Since we have an odd number of values, this tells us that the median is part of the data set. It's the middle most item after we sort the values.

Recall that the mode is the most frequent item. Since the mode and median are the same, this must mean x can only be equal to one of the following

4, 9, 7 or 8

We can only pick one of those values.

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

If x = 4, then the set {4,9,7,8,x} updates to {4,9,7,8,4} which sorts to {4,4,7,8,9}

The middle most item is in slot 3, which would be 7. So the median is 7.

The median 7 does not match with the mode 4.

So we cross x = 4 off the list.

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

If x = 7, then we have {4,7,7,8,9}

The mode is 7 and the median is 7. So far, so good.

Now let's compute the mean. Add up the values and divide by 5 because there are 5 items.

(4+7+7+8+9)/5 = 35/5 = 7

We've shown that the set {4,7,7,8,9} has mean 7.

Overall, that set has the same mean, median and mode. So the answer is confirmed.

I'll let you check the cases when x = 8 and x = 9.

Answer:

FALSE

Step-by-step explanation:

First, define y and x.

In statistics, we have what we call variables. Variables are items or symbols that can take on various values. We have dependent variables - whose values are derived from other variables in an equation - and independent variables - whose values are given and are used to determine the values of dependent variables.

Usually, y represents the dependent variable while x represents the independent variable. So the simplest form of regression equation is

y = f (x)

Said as "y is a function of x"

A logistic regression equation can be used to calculate y when x values are given.

Here, the independent variable function (the X function) is a logistic function and it is used to find a binary dependent variable (a Y value, out of two possible values).

In logistic regression equations, the value of Y is not numerical like 1, 0.2, 3/4, and so on. It is categorical, e.g.

Black/White, Gain/Lose, Pass/Fail, Eat/Drink, etc.

Answer:

Step-by-step explana

540

Answer:

if you mean 15k as is 15 thousand then the answer would be 15,010

Answer:

35

Step-by-step explanation:

7-7(-4)

Using PEMDAS

Multiply first

7 +28

Then add

35

////////////////////////

9514 1404 393

Answer:

  13

Step-by-step explanation:

152AB1 is not a square in hexadecimal, so we assume A and B are supposed to represent single digits in decimal.

If A=B=0, √152001 ≈ 389.9

If A=B=9, √152991 ≈ 391.1

The least significant digit of 152AB1 being non-zero, we know it is not the square of 390. Hence, it must be the square of 391.

For 152AB1 to be a perfect square, we must have ...

  152AB1 = 391² = 152881

The sum of the digits of the square root is 3+9+1 = 13.

9514 1404 393

Answer:

  see attached

Step-by-step explanation:

Each point moves to the same distance on the other side of the mirror line. The slope of the mirror line is 1, so the points move along a line perpendicular to that, one with a slope of -1. You can make sure the distances are the same by counting the grid squares.

Answer:

The answer is below

Step-by-step explanation:

Transformation is the movement of a point from its initial location to a new location. Types of transformation are rotation, reflection, translation and dilation.

If a point A(x, y) is translated a units right and b units up, the new point is at A'(x + a, y + b).

If a point A(x, y) is reflected across the line y = -x, the new point is at A'(-y, -x).

If a point A(x, y) is rotated counterclockwise by 270 degrees, the new point is at A'(y, -x).

Let us assume that triangle ABC has vertices at A(-6, -1), B(-3, -3) and C(-1, -2).

If it is moved 5 units to the right and 2 units up, the new point is at A'(-1, 1), B'(1, -1) and C'(3, 0). If it is reflected across the line y = -x, the vertices are at A"(-1, 1), B"(1, -1) and C"(0, -3). If it is then rotated counterclockwise about the origin by 270°, the new point is at A'"(-1, -1), B"'(1, 1), C"'(3, 0)

Answer:

27405

Step-by-step explanation:

There are 6 different variants available for each croissant. There are 26 croissants in all out of which 1 is plain. We use combination and permutation technique to identify different ways to choose croissant.

[5 + 26 - 1 ] 26 = 30C26 = 27405.

Use Bayes Theorem to compute that probability. I will denote bath as [tex]B[/tex] and nap as [tex]N[/tex], the probability will be denoted as [tex]P(B)[/tex] or [tex]P(N)[/tex].

By Bayes Theorem

[tex]P(B\mid N)=\frac{P(N\mid B)\cdot P(B)}{P(N)}[/tex]

Which reads,

"What is the probability of [tex]B[/tex] given [tex]N[/tex]".

We know that [tex]P(N\mid B)[/tex] is 1 because we already took a bath. So the formula simplifies to,

[tex]P(B\mid N)=\frac{P(B)}{P(N)}[/tex]

Now insert the data,

[tex]P(B\mid N)=\frac{1/5}{4/5}=\boxed{\frac{1}{4}}[/tex]

So the probability that you will take a bath is [tex]0.25[/tex] after you have taken a nap.

Hope this helps. :)

Answer:

A (1 + i)^n = 1490    time for amount to reach 1490

(1 + i)^n = 1.49    since A = $1000

n log (1 + .06/4) = log 1.49       take log of both sides at 1.5% per quarter

n = log (1.49) / log 1.015  = 26.78 periods or 6.695 years

(compare to 6.843 years compounded annually)

[tex]t = ln(A/P) / n[ln(1 + r/n)]\\t = ln(1,490.00/1,000.00) / ( 4 * [ln(1 + 0.06/4)] )\\t = ln(1,490.00/1,000.00) / ( 4 * [ln(1 + 0.015)] )\\t = 6.7 years[/tex]

It would take around 6 years 8 months to get $1,490 from $1,000 at 6%.

I hope I've helped! :)