I need help with the following question

Answer: The value of x- 2y is a. [tex]\pm 3[/tex].

Step-by-step explanation:

Given:  x and y are two positive real numbers such that [tex]x^2+4y^2=17[/tex]   and [tex]xy= 2[/tex] .

Consider [tex](x-2y)^2=x^2-2(x)(2y)+(2y)^2\ \ \ [(a+b)^2=(a^2-2ab+b^2)][/tex]

[tex]=x^2-4xy+4y^2[/tex]

[tex]=x^2+4y^2-4(xy)[/tex]

Put  [tex]x^2+4y^2=17[/tex]   and [tex]xy= 2[/tex] , we get

[tex](x-2y)^2=17-4(2)=17-8=9[/tex]

[tex]\Rightarrow\ (x-2y)^2=9[/tex]

Taking square root on both sides , we get'

[tex]x-2y= \pm3[/tex]

Hence, the value of x- 2y is a. [tex]\pm 3[/tex].

Answer:

13 units

Step-by-step explanation:

Use the equation of a circle, (x - h)² + ( y - k )² = r², where (h, k) is the center and r is the radius.

Plug in the values and solve for r:

(5 - 0)² + (12 - 0)² = r²

25 + 144 = r²

169 = r²

13 = r

Answer:

D.

Step-by-step explanation:

In direct variations, we would have:

[tex]q=kr[/tex]

Where k is some constant.

Since this is indirect variation, instead of that, we would have:

[tex]q=\frac{k}{r}[/tex]

To determine the equation, find k by putting in the values for q and r:

[tex]10=\frac{k}{2.5}\\k=2.5(10)=25[/tex]

Now plug this back into the variation:

[tex]q=\frac{25}{r}[/tex]

The answer is D.

Answer:

£32 in total for the top and two trousers

Step-by-step explanation:

The price for a top In the "cloth for you" shop= £10

The price for a bermuda trouser In the "cloth for you" shop= £12

There is a 20% discount on tops

The price If I bought one top and would trouser will be

(10-(0.2*10)) for the top

2(12) for the trouser

Total= (10-(0.2*10))+ 2(12)

Total = 10-2+24

Total = £32

So I spent £32 in total for the top and two trousers

Answer:

Step-by-step explanation:

Let the speed of Frank be x and speed of Gregory be y. If Gregory drives 22 miles per hour faster than Frank, then y = 22+x. SInce they they are 216miles apart after 2.25 hours,

Speed = Distance/Time

Total time travelled by them = 2.25hours

Total distance = 216 hours

Total speed = x+y = x+22+x

Substituting this parameters into the formula given to get x we will have;

x+22+x = 216/2.25

2x+22 = 96

2x = 96-22

2x = 74

x = 74/2

x = 37

Hence the speed of Frank is 37miles per hour while that of gregory is 37+22 = 59miles/hour

====================================================

Explanation:

Both AB and XY are the first two letters of ABC and XYZ respectively. So we have one fraction of AB/XY = 2/7.

AC and XZ are the first and last letters of ABC and XYZ respectively. We can form another fraction AC/XZ. I'm dividing in the same order of small over large to keep things consistent. As you can probably guess, the order of the letters ABC and XYZ are important so we see how the angles match up and how the proportional sides match up.

Because the triangles are similar, the two fractions formed earlier are equal to one another.

The equation we need to solve is AB/XY = AC/XZ

-----

AB/XY = AC/XZ

2/7 = 3/N ... plug in given values

2N = 7*3 .... cross multiply

2N = 21

N = 21/2 .... divide both sides by 2

N = 10.5

ZX is 10.5 units long.

Answer:

x = 1

Step-by-step explanation:

First, move all the variables to one side by subtracting 5x on both sides:

5x + 2 = 12x - 5

2 = 7x - 5

Add 5 to both sides:

7 = 7x

1 = x

Answer:

x=1

Step-by-step explanation:

5x + 2 =12x- 5

Subtract 5x from each side

5x-5x + 2 =12x-5x- 5

2 = 7x-5

Add 5 to each side

2+5 = 7x-5+5

7 = 7x

Divide each side by 7

7/7 = 7x/7

1 =x

Answer: 56.9 years to 63.1 years.

Step-by-step explanation:

Confidence interval for population mean (when population standard deviation is unknown):

[tex]\overline{x}\pm t_{\alpha/2}{\dfrac{s}{\sqrt{n}}}[/tex]

, where [tex]\overline{x}[/tex]= sample mean, n= sample size, s= sample standard deviation, [tex]t_{\alpha/2}[/tex]= Two tailed t-value for [tex]\alpha[/tex].

Given: n= 24

degree of freedom = n- 1= 23

[tex]\overline{x}[/tex]= 60 years

s= 7.4 years

[tex]\alpha=0.05[/tex]

Two tailed t-critical value for significance level of [tex]\alpha=0.05[/tex] and degree of freedom 23:

[tex]t_{\alpha/2}=2.0687[/tex]

A 95% confidence interval on the true mean age:

[tex]60\pm (2.0686){\dfrac{7.4}{\sqrt{24}}}\\\\\approx60\pm3.1\\\\=(60-3.1,\ 60+3.1)\\\\=(56.9,\ 63.1)[/tex]

Hence, a 95% confidence interval on the true mean age. : 56.9 years to 63.1 years.

Answer:

[tex]\boxed{\sqrt{65}}[/tex]

Step-by-step explanation:

Magnitude is solved with the following equation: [tex]\sqrt{x^{2}+y^{2}}[/tex]

Therefore, just plug in your x and y-values and solve.

[tex]\sqrt{4^{2}+7{^{2}}[/tex]

[tex]\sqrt{16 + 49}[/tex]

[tex]\sqrt{65}[/tex]

Because [tex]\bold{\sqrt{65}}[/tex] cannot be simplified further, this is the magnitude of the vector.

Answer:

[tex]\huge\boxed{6 ( 3d + 2 )}[/tex]

Step-by-step explanation:

18d + 12

The greatest common factor is 6, So we need to factor out 6

=> 6 ( 3d + 2 ) [Distributive property has been applied and this is the simplest form]

Answer:

6(3d+2)

Step-by-step explanation:

6 is the gcd of the two terms.

Answer:

35%

Step-by-step explanation:

[tex]Principal = 2500\\\\Simple\:Interest = 3500\\\\Time = 4 \:years\\\\Rate = ?\\\\Rate = \frac{100 \times Simple \: Interest }{Principal \times Time}\\\\Rate = \frac{100 \times 3500}{2500 \times 4} \\\\Rate = \frac{350000}{10000}\\\\ Rate = 35 \%[/tex]

[tex]S.I = \frac{PRT}{100}\\\\ 100S.I = PRT\\\\\frac{100S.I}{PT} = \frac{PRT}{PT} \\\\\frac{100S.I}{PT} = R[/tex]

Answer:

35%

Step-by-step explanation:

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Answer:

c=18

Step-by-step explanation:

5/30=3/c

1/6=3/18

1✖️3=3

6✖️3=18

Answer:

0.9719

Step-by-step explanation:

Find the mean and standard deviation of the sampling distribution.

μ = 5.1

σ = 1.1 / √49 = 0.157

Find the z score.

z = (x − μ) / σ

z = (4.8 − 5.1) / 0.157

z = -1.909

Use a calculator to find the probability.

P(Z > -1.909)

= 1 − P(Z < -1.909)

= 1 − 0.0281

= 0.9719

The probability of the randomly used item mean length is greater than 4.8 inches is 0.9719

Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true.

In statistics, the standard deviation is a measure of the amount of variation or dispersion of a set of values.

The arithmetic mean is found by adding the numbers and dividing the sum by the number of numbers in the list.

Given,

Mean = 5.1 inches

Standard deviation = 1.1 inches

Sample size = 49

New mean = 4.8

Z score = Difference in mean /(standard deviation / [tex]\sqrt{sample size}[/tex])

Z score = [tex]\frac{4.8-5.1}{1.1/\sqrt{49} }=-1.909[/tex]

Z score = -1.909

Then the probability

P(Z>-1.909)

=1-P(Z>-1.909)

=1-0.0281

=0.9719

Hence, The probability of the randomly used item mean length is greater than 4.8 inches is 0.9719

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Answer:

k = 5

Step-by-step explanation:

I will assume that your polynomial is

x^2 - 3x^2 + kx + 14

If x - a is a factor of this polynomial, then a is a root.

Use synthetic division to divide (x - 2) into x^2 - 3x^2 + kx + 14:

 2      /      1     -3     k     14

                        2     -2    2k - 4

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

               1        -1    (k - 2)   2k - 10

If 2 is a root (if x - 2 is a factor), then the remainder must be zero.

Setting 2k - 10 = to zero, we get k = 5.

The value of k is 5 and the polynomial is x^2 - 3x^2 + 5x + 14

Aqui temos a seguinte divisao de terreno:

creche + banheiros + academia = 45% + 3% + 12% = 60%

O que sobra: Fazendo a conta, 100 - 60 = 40, restará 40%

No enunciado informa que sobraram 960m².

Logo concluimos que 40% = 960m²

Sendo assim, regra de 3:

   m²                %

  960   --------   40

    X     --------   60

40X = 960 . 60

X = 57600/40

X = 1440

Logo 1440m² é destinado para: creche, banheiros públicos e academia

de ginástica comunitária.

O terreno tem um total de 1440 + 960 = 2400m²

para cada espaço - novamente diversas regra de 3:

→ creche = 45%

    m²                  %

  2400   --------   100

    X        --------    45

X = 108000/100 = 1080

→ banheiros públicos  = 3%

    m²                  %

  2400   --------   100

    X        --------    3

X = 7200/100 = 72

→ academia de ginástica comunitária = 12%

    m²                  %

  2400   --------   100

    X        --------    12

X = 28800/100 = 288

provando:

60% = 1440m²  (visto acima)

creche - 1080

banheiros - 72

academia - 288

1080 + 72 + 288 = 1440 (60%)

Answer:

[tex]\boxed{50}[/tex]

Step-by-step explanation:

Because the initial temperature is 40 degrees and it increases by 10, add the two values together to get the final temperature.

40 + 10 = 50

Therefore, the final answer is 50 degrees.

Answer:

50

Step-by-step explanation:

If it starts at 40 degrees and increases 10 degrees, it is going to be 50 degrees.  Increases means adding, so it is asking you to add 10 to 40 which is 50.  If it asks decreases in the future you will have to subtract.

[tex]\displaystyle\\(a+b)^n\\T_{r+1}=\binom{n}{r}a^{n-r}b^r\\\\\\(x+2)^7\\a=x\\b=2\\r+1=5\Rightarrow r=4\\n=7\\T_5=\binom{7}{4}x^{7-4}2^4\\T_5=\dfrac{7!}{4!3!}\cdot x^3\cdot16\\T_5=16\cdot \dfrac{5\cdot6\cdot7}{2\cdot3}\cdot x^3\\\\T_5=560x^3[/tex]

Answer:

[tex]\large \boxed{560x^3}[/tex]

Step-by-step explanation:

[tex](x+2)^7[/tex]

Expand brackets.

[tex](x+2) (x+2) (x+2) (x+2) (x+2) (x+2) (x+2)[/tex]

[tex](x^2 +4x+4) (x^2 +4x+4) (x^2 +4x+4)(x+2)[/tex]

[tex](x^4 +8x^3 +24x^2 +32x+16)(x^3 +6x^2 +12x+8)[/tex]

[tex]x^7 +14x^6 +84x^5 +280x^4 +560x^3 +672x^2 +448x+128[/tex]

The fifth term is 560x³.

Answer:

Number of levels = 2

Type of design = Repeated measure

Dependent variable = Typing Speed

Step-by-step explanation:

The number of levels in an experiment simply refers to the number of experimental conditions in which participants are subjected to. In the scenario above, the number of levels is 2. Which are ; Halfway through the class and After the class is over.

The type of designed employed is REPEATED MEASURE, this is because the participants all took part in each experimental condition.

The dependent variable is TYPING SPEED, which is the variable which is measured with respect to the independent variable. Hence the observed value depends on period that is (halfway through the class or after the class is over).

Answer: Negative sign

Adding two negative values results in another negative value.

-1.69 + (-1.69) = -3.38

It's like starting $1.69 in debt and then adding 1.69 dollars of more debt. You'll slide further into debt being $3.38 in debt total.

The sign is negative as the value of -1.69 + (-1.69) is -3.38.

An expression is a way of writing a statement with more than two variables or numbers with operations such as addition, subtraction, multiplication, and division.

Example: 2 + 3x + 4y = 7 is an expression.

We have,

-1.69 + (-1.69)

= -1.69 - 1.69

= -3.38

This means,

The sign is negative.

Thus,

The value of -1.69 + (-1.69) is -3.38.

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Answer: The missing number is 5.

Step-by-step explanation:

In the table we can only have numbers between 1 and 9,

The pattern that i see is:

We have sets of 3 numbers.

"the bottom number is equal to the difference between the two first numers, if the difference is negative, change the sign, if the difference is zero, there goes a 9 (the next number to zero)"

Goin from right to left we have:

9 - 6 = 3

6 - 2 = 4

4 - 9 = - 5 (is negative, so we actually use -(-5) = 5)

4 - 4 = 0 (we can not use zero, so we use the next number, 9)

3 - 3 = 0 (same as above)

? - 1 = 4

? = 4 + 1 =  5

The missing number is 5.

Answer:

  a) position 22

  b) 26

  c) shuffle 25

Step-by-step explanation:

Assuming the shuffling occurs so that the bottom card of the top half of the deck (card 26) becomes the bottom card (card 52), while the top card of the bottom half (card 27) becomes the top card (card 1), the sequence of card 1 positions with successive shuffles is ...

  {2, 4, 8, 16, 32, 11, 22, 44, 35, 17, 34, 15, 30, 7, 14, 28, 3, 6, 12, 24, 48, 43, 33, 13, 26, 52, 51, 49, 45, 37, 21, 42, 31, 9, 18, 36, 19, 38, 23, 46, 39, 25, 50, 47, 41, 29, 5, 10, 20, 40, 27, 1}

That is, after the first shuffle, card 1 is at position 2; after the second shuffle, it is at position 4; and so on.

(a) Hence the position of card 1 after the 7th shuffle is 22.

__

(b) The top card is in position 52 after 26 shuffles.

__

(c) The top card is in position 26 after 25 shuffles; the bottom card is in position 27 after 25 shuffles. That is when they first touch. (They touch again after 51 shuffles.)

Answer:

125π ft²

Step-by-step explanation:

1/4π(30)² - 1/4π(20)² = 125π

Answer:

[tex] Perimeter = 3x + 3 [/tex]

Step-by-step explanation:

Perimeter of the given triangle in the figure is the sum of all three sides.

The expressions for the 3 sides are given as, [tex] x, (x - 3), (x + 6) [/tex].

Therefore,

[tex] Perimeter = x + (x - 3) + (x + 6) [/tex]

Simplify,

[tex] Perimeter = x + x - 3 + x + 6 [/tex]

Collect like terms

[tex] Perimeter = x + x + x - 3 + 6 [/tex]

[tex] Perimeter = 3x + 3 [/tex]

Answer:

The percentage of variation in the dependent variable explained by the variation in the independent variable is 80 %.

Step-by-step explanation:

A coefficient of correlation of 0.8 means that dependent variable changes in 0.8 when independent variable changes in a unit. Hence, the percentage of such variation ([tex]\%R[/tex]) is:

[tex]\%R = \frac{\Delta y}{\Delta x}\times 100\,\%[/tex]

Where:

[tex]\Delta x[/tex] - Change in independent variable, dimensionless.

[tex]\Delta y[/tex] - Change in dependent variable, dimensionless.

If [tex]\Delta x = 1.0[/tex] and [tex]\Delta y = 0.8[/tex], then:

[tex]\%R = 80\,\%[/tex]

The percentage of variation in the dependent variable explained by the variation in the independent variable is 80 %.

Answer:

Hey there!

The third graph, with a maximum at (-1, -3) is the correct choice.

Let me know if this helps :)

Answer:

see below

Step-by-step explanation:

f(x) = –(x + 1)^2 – 3

We know that this is a parabola in the form

y = a( x-h)^2 +k

where ( h,k) is the vertex

y = -1( x- -1)^2 + -3

a is negative so the parabola opens downward

( -1,-3) is the vertex

The intervals would contain approximately 95% of the measurements will be (120, 280). Then the correct option is C.

The Gaussian Distribution is another name for it. The most significant continuous probability distribution is this one. Because the curve resembles a bell, it is also known as a bell curve.

In numerical documentation, these realities can be communicated as follows, where Pr(X) is the likelihood capability, Χ is a perception from an ordinarily circulated irregular variable, μ (mu) is the mean of the dispersion, and σ (sigma) is its standard deviation:

The interval for 95% will be given as,

Pr(X) = μ ± 2σ

Pr(X) = 200 ± 2(40)

Pr(X) = 200 ± 80

Pr(X) = (200 - 80, 200 + 80)

Pr(X) = (120, 280)

The intervals would contain approximately 95% of the measurements will be (120, 280). Then the correct option is C.

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Answer:

[tex]f(a) = 2a + 8[/tex]

[tex]f(x + h) = 2x + 2h + 8[/tex]

[tex]\frac{f(x + h) - f(x)}{h} = 2[/tex]

Step-by-step explanation:

Given

[tex]f(x) = 2x + 8[/tex]

Required

[tex]f(a)[/tex]

[tex]f(x + h)[/tex]

[tex]\frac{f(x + h) - f(x)}{h}[/tex]

Solving for f(a)

Substitute a for x in the given parameter

[tex]f(x) = 2x + 8[/tex] becomes

[tex]f(a) = 2a + 8[/tex]

Solving for f(x+h)

Substitute x + h for x in the given parameter

[tex]f(x + h) = 2(x + h) + 8[/tex]

Open Bracket

[tex]f(x + h) = 2x + 2h + 8[/tex]

Solving for [tex]\frac{f(x + h) - f(x)}{h}[/tex]

Substitute 2x + 2h + 8 for f(x + h), 2x + 8 fof f(x)

[tex]\frac{f(x + h) - f(x)}{h}[/tex] becomes

[tex]\frac{2x + 2h + 8 - (2x + 8)}{h}[/tex]

Open Bracket

[tex]\frac{2x + 2h + 8 - 2x - 8}{h}[/tex]

Collect Like Terms

[tex]\frac{2x - 2x+ 2h + 8 - 8}{h}[/tex]

Evaluate the numerator

[tex]\frac{2h}{h}[/tex]

[tex]2[/tex]

Hence;

[tex]\frac{f(x + h) - f(x)}{h} = 2[/tex]

Answer:

B =

[tex]4x - 1 - \frac{4}{2x - 3} [/tex]

Step-by-step explanation:

In this type of questions the answers are required in the

[tex]quotient \: + \frac{remainder}{divisor} [/tex]

form.

First of all, the equations in question must be arranged properly

[tex](8 {x}^{2} - 14x - 1) \div 2x - 3[/tex]

Then you divide.

[tex]2x - 3 \sqrt{8 {x}^{2} - 14x - 1 } [/tex]

Answer

[tex]4x - 1 - \frac{4}{2x - 3} [/tex]

Answer:

102 cm

Step-by-step explanation:

Answer:

So (1,3) is a vertex (out of two) of the hyperbola.

Step-by-step explanation:

The vertices are marked by the dot on the hyperbola.

They are (1,3) and (1,-7).

However, (1,-7) is not on the list of answer choices, but (1,3) is.

So (1,3) is a vertex (out of two) of the hyperbola.

So (1,3) is a vertex (out of two) of the hyperbola.

a plane curve generated by a point so moving that the difference of the distances from two fixed points is a constant : a curve formed by the intersection of a double right circular cone with a plane that cuts both halves of the cone.

According to the question

The vertices are marked by the dot on the hyperbola.

They are (1,3) and (1,-7).

However, (1,-7) is not on the list of answer choices, but (1,3) is.

Hence , (1,3) is a vertex (out of two) of the hyperbola.

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