A control variable is:
A. Measured to show the effect of a change.
B. Kept the same to make an experiment a fair test.
C. Collected to draw conclusions.
D. Changed to test a hypothesis.

It’s in between a and b, they’re both technically true no?

Answer:

B

Step-by-step explanation:

(3x+1)/x² - 5x

we can only simplify this by bringing both terms to the same denominator : x²

to achieve this we need to multiply 5/x by x/x (remember, to keep the value of a term unchanged, we need to multiply numerator and denominator with the same values).

so, we get

(3x+1)/x² - 5x/x² = (3x+1-5x)/x² = (-2x+1)/x²

therefore, B is correct

Answer:

The equation of the parabola with a focus at (2,4) and a directrix of y=8 is,

48-8y=(x-2)²

Answer:

(0,2)

Step-by-step explanation:

The y intercept is the value on the y axis where it crosses.  The x value is zero

It crosses at y =2 and x=0

(0,2)

Answer:

this and that and that is this

Step-by-step explanation:

step by step

Answer: 90 sides

Step-by-step explanation:

Let's say the circle has a center at  A and B and C are at the vertices of a polygon. Since this figure is inscribed in a circle, we can draw two radii through the vertices. Because all radii are congruent, we know segment BA is congruent to Segment CA. If a triangle has at least 2 congruent sides, we can identify the triangle as an isosceles triangle. With this we can conclude <ACB is congruent to <ABC. By the definition of congruent angles, m<ACB = M<ABC. Let's say m<ACB = x. By the Triangle Sum Theorem, 40 + x + m<ABC = 180. By substitution, 40 + x + x = 180. When we solve we get x =70. Since radii bisect interior angles we know that each interior angle of this polygon is 140 degrees. If we plug in 140 to our equation, [tex]\frac{(n-2)180}{n}[/tex]  where n is the number of sides, we get n = 90. So we can conclude this polygon has 90 sides

63-(-3)(-2-8-3) = 3(5+(-2)(-1))

63-(6+24+9) = 3(5+(2))

63-(39) = 3(7)

24 ≠ 21

Answered by Gauthmath must click thanks and mark brainliest

Answer:

Option C, 95°

Step-by-step explanation:

180-121 = 59

180-144 = 36

third angle of the triangle is, 180-59-36 = 85,

missing angle n = 180-85 = 95°

Answered by GAUTHMATH

Answer:

strong and fexible .

variable

Answer:

The sample size must be of 47,059,600.

Step-by-step explanation:

We have 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 - 0.95}{2} = 0.025[/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 p-value of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

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.

Standard deviation:

[tex]\sigma = 3.5[/tex]

If you want the error bound E of a 95% confidence interval to be less than 0.001, how large must the sample size n be?

This is n for which M = 0.001. So

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

[tex]0.001 = 1.96\frac{3.5}{\sqrt{n}}[/tex]

[tex]0.001\sqrt{n} = 1.96*3.5[/tex]

[tex]\sqrt{n} = \frac{1.96*3.5}{0.001}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.96*3.5}{0.001})^2[/tex]

[tex]n = 47059600[/tex]

The sample size must be of 47,059,600.

Answer:

80 numbers

Step-by-step explanation:

(6 - 2(because when the hundreds is 5 or 6, it will higher than 500)) x 5 x 4 = 80

Answer:

4y

They would have the same value if a number was substituted for y

Step-by-step explanation:

y+y+2y =

Combine like terms

4y

These are all like terms

They would have the same value if a number was substituted for y

Let y = 5

5+5+2(5) = 5+5+10 = 20

4(5) =20

Answer:

16 and 3

Step-by-step explanation:

Let x and y represent the positive integers. We know that

[tex]x + y = 19[/tex]

[tex]xy = 48[/tex]

Isolate the top equation for the x variable.

[tex]x = 19 - y[/tex]

Substitute into the second equation.

[tex](19 - y)y = 48[/tex]

[tex]19y - {y}^{2} = 48[/tex]

[tex] - {y}^{2} + 19y = 48[/tex]

[tex] - {y}^{2} + 19y - 48[/tex]

[tex](y - 16)(y - 3)[/tex]

So our values are

16 and 3.

Answer:

5 cm

Step-by-step explanation:

Let x = width of frame.

The width of the frame is added all around the painting, so you must add 2x to the length of the painting and 2x to the width of the painting to find the total length and width including the frame.

painting length: 30

total length: 2x + 30

painting width: 20

total width: 2x + 20

total area = LW

total area = (2x + 30)(2x + 20)

total area = 1200

(2x + 30)(2x + 20) = 1200

(x + 15)(x + 10) = 300

x^2 + 10x + 15x + 150 = 300

x^2 + 25x - 150 = 0

(x - 5)(x + 30) = 0

x - 5 = 0  or  x + 30 = 0

x = 5  or x = -30

The width of the frame cannot be a negative number, so we discard the solution x = -30.

Answer: 5 cm

Answer:

524m

Step-by-step explanation:

Hence the time that the ball will be height than 12 feet off the ground is 4secs

Given the expression for calculating the height in  feet as;

h(t) = -4t²+16t

If the ball is higher than 12feet, h(t) > 12

Substituting h = 12 into the expression

-4t²+16t > 12

-4t²+16t - 12 > 0

4t²- 16t + 12 > 0

t²- 4t + 3 > 0

Factorize

(t²- 3t)-(t + 3) > 0

t(t-3)-1(t-3) > 0

(t-1)(t-3)>0

t > 1 and 3secs

Hence the time that the ball will be height than 12 feet off the ground is 4secs

Learn more: https://brainly.com/question/18405392

Answer:

10 or -10,

Read the explanation

Step-by-step explanation:

Rewrite this problem as a numerical expression. As per the wording of this problem, there can be two expressions derived.

1.     [tex]((\frac{1}{6}(10*3)*4)-30[/tex]

2.     [tex]30-((\frac{1}{6}(10*3)*4)[/tex]

Simplify, remember the order of operations. The order of operations is the sequence by which one is supposed to perform operations in a numerical expression. This order is the following:

1. Parenthesis

2. Exponents

3. Multiplication or division

4. Addition or Subtraction

Use this sequence when simplifying and solving the expression:

Expression 1

[tex]((\frac{1}{6}(10*3)*4)-30\\\\=((\frac{1}{6}(30)*4)-30\\\\=(5*4)-30\\\\=20 - 30\\\\= -10[/tex]

Expression 2

[tex]30-((\frac{1}{6}(10*3)*4)\\\\=30-((\frac{1}{6}(30)*4)\\\\=30-(5*4)\\\\= 30-20\\\\= 10[/tex]

The equation of the reflected function across the y-axis is g(x) = -4x - 8.

A statement, principle, or policy that creates the link between two variables is known as a function. Functions are found all across mathematics and are required for the creation of complex relationships.

The function f(x) = 4x - 8 is reflected across the y-axis.

The function g(x) will be given by putting the negative x in place of x. Then the reflected function is obtained.

g(x) = -4x - 8

Then the equation of the reflected function across the y-axis is g(x) = -4x - 8.

The graph of the reflected graph is given below.

More about the function link is given below.

https://brainly.com/question/5245372

#SPJ2

Answer:

y = 3x+2

Step-by-step explanation:

First find the slope using the slope formula

m= (y2-y1)/(x2-x1)

   = ( -1 - -4)/(-1 - -2)

   = (-1 +4)/ (-1 +2)

   = 3/1

  = 3

The slope intercept formula is

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

y = 3x+b

Using the point (-1,-1) and substituting into the equation

-1 = 3(-1)+b

-1 = -3+b

-1+3 = b

2 = b

y = 3x+2

Answer:

6.286;

0.0165

0.976

0.1995

Step-by-step explanation:

Given that :

Mean, μ = 243. 4

Standard deviation, σ = 35

Sample size, n = 31

1.)

Standard Error

S. E = σ / √n = 35/√31 = 6.286

2.)

P(x < 230) ;

Z = (x - μ) / S.E

P(Z < (230 - 243.4) / 6.286))

P(Z < - 2.132) = 0.0165

3.)

P(x > 231)

P(Z > (231 - 243.4) / 6.286))

P(Z > - 1.973) = 0.976 (area to the right)

4)

P(x < 248)

P(Z < (248 - 243.4) / 6.286))

P(Z < 0.732) = 0.7679

P(x < 255)

P(Z < (255 - 243.4) / 6.286))

P(Z < 1.845) = 0.9674

0.9674 - 0.7679 = 0.1995

Answer:

The square root of -9 cannot be -3 because -3 squared or -3 times -3 equals 9 not -9.

Hope this helps!

Answer:

(0, 3)

Step-by-step explanation:

y = 3 is the horizontal tangent to y = x^2+3, and passes the parobala at (0, 3)

Answer:

D.

Step-by-step explanation:

sin Y = opposite side / hypotenuse

= 38/63.

Answer:

D

Step-by-step explanation:

[tex]Sin \ y = \frac{opposite \ side}{hypotenuse}\\\\Sin \ y = \frac{38}{63}[/tex]

Answer:

30.2

Step-by-step explanation:

We know that quadrilateral KLMN is larger than quadrilateral GHIJ by a scale factor. In order to figure out that scale factor, we must divide a value of a side of KLMN by the value of the side that it corresponds to on GHIJ. One said side is NM, because we know it corresponds to JI on GHIJ. The value of NM is 56, and the value of JI is 13, so to figure out the scale factor, we must divide 56 by 13. We have the scale factor as 56/13, so to figure out the measure of side NM, we must find the side it corresponds to on GHIJ. The side it corresponds to is side JG, which has a value of 7. To get the value of NK, we must multiply the scale factor by 7, and the scale factor is 56/13. 56/13 times 7 is equal to 392/13. Rounding to the nearest tenth, we have the answer as 30.2

Answer:

(C) The value of r indicates that the number of sales decreases as the price increases.

ED2021.

The best statement, given the correlation coefficient of -0.63 is: value of r indicates that the number of sales decreases as the price increases.

A negative correlation coefficient has a negative sign, and implies a negative relationship between two variables.

This means that, as one variable decreases, the other variable increases.

Thus, a correlation coefficient of -0.63 shows a negative relationship between prices of smartphones and the number of sales.

Therefore, the best statement, given the correlation coefficient of -0.63 is: value of r indicates that the number of sales decreases as the price increases.

Learn more about correlation coefficient on:

https://brainly.com/question/4219149

Recall that

[tex]L_s\left\{t^n\right\} = \dfrac{n!}{s^{n+1}}[/tex]

where [tex]L_s\left\{y(t)\}[/tex] is the Laplace transform of y(t) into the s-domain.

Then you have

[tex]L_s\left\{t+t^2+t^3\right\} = \dfrac{1!}{s^{1+1}} + \dfrac{2!}{s^{2+1}} + \dfrac{3!}{s^{3+1}} = \boxed{\dfrac1{s^2} + \dfrac2{s^3} + \dfrac6{s^4}}[/tex]

Answer:

y = 2/3x-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 = 2/3x +b

Using the point (-6,-5)

-5 = 2/3(-6)+b

-5 = -4 +b

Add 4 to each side

-5+4 = b

-1 =b

y = 2/3x-1

Answer:

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

Step-by-step explanation:

[tex]y = mx + c \\ \\ m = slope \\ c = y \: \: intercrept[/tex]

[tex]m = \frac{2}{3} [/tex]

[tex]y = mx + c \\ - 5 = \frac{2}{3} \times - 6 + c \\ - 5 = \frac{ - 12}{3} + c \\ - 5 = - 4 + c \\ - 5 + 4 = c \\ - 1 = c[/tex]

So, the equation of the line is,

[tex]y = mx + c \\ y = \frac{2}{3}x - 1 [/tex]

Answer:

1.23

Step-by-step explanation:

Answer:

[tex]x=5[/tex]

[tex]h=\sqrt{(5)^{2}+x^{2} } =\sqrt{(5)^{2}+(5)^{2} }[/tex]

[tex]h=\sqrt{25+25} =\sqrt{50}[/tex]

[tex]h=5\sqrt{2}[/tex]

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