4x^2-400=0

square roots and solving quadratics

Answer:

152 ft.

Step-by-step explanation:

19*8 = 152

Answer:

a. The point estimate was of $44,600.

b. The sample size was of 16.

Step-by-step explanation:

Confidence interval concepts:

A confidence interval has two bounds, a lower bound and an upper bound.

A confidence interval is symmetric, which means that the point estimate used is the mid point between these two bounds, that is, the mean of the two bounds.

The margin of error is the difference between the two bounds, divided by 2.

a. What is the point estimate of the mean salary for all college graduates in this town?

Mean of the bounds, so:

(38737+50463)/2 = 44600.

The point estimate was of $44,600.

b. Determine the sample size used for the analysis.

First we need to find the margin of error, so:

[tex]M = \frac{50463-38737}{2} = 5863[/tex]

Relating the margin of error with the sample size:

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 - 0.9}{2} = 0.05[/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 - 0.05 = 0.95[/tex], so Z = 1.64.

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.

For this problem, we have that [tex]\sigma = 14300, M = 5863[/tex]. So

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

[tex]5863 = 1.645\frac{14300}{\sqrt{n}}[/tex]

[tex]5863\sqrt{n} = 1.645*14300[/tex]

[tex]\sqrt{n} = \frac{1.645*14300}{5863}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.645*14300}{5863})^2[/tex]

[tex]n = 16[/tex]

The sample size was of 16.

Answer:

0,0

Step-by-step explanation:

Question:

c=3x+80  

R=12x- 0.02x^2

R= revenue  

C=cost  

X=items sold  

A) 9x-(0.2x^2+80)

B) x(9-0.2x)-80  

C) x(9-0.02x)

D) 9x-0.02x^2+80

Answer:

c) x(9-0.2x)

is the correct answer

PLZ MARK BRAINLIEST

Answer:

P = 40 x 4

= 160

P = 50 x 3

= 150

Answer:

The center (-3, 0)

9514 1404 393

Answer:

Step-by-step explanation:

The desired parameters can be found by putting the equation into the standard form for the equation of a circle:

  (x -h)^2 +(y -k)^2 = r^2 . . . . . circle centered at (h, k) with radius r

The values of h and k will be half the coefficients of the linear x- and y-terms, respectively.

  x^2 +6x +9 +y^2 -7 = 9 . . . . . add 9 to complete the square

  (x +3)^2 +y^2 = 16 . . . . . . . . . add 7 to get the desired form

This equation shows us (h, k) = (-3, 0) and r = 4.

The center is (-3, 0), and the radius is 4.

Answer: An expression [tex]3 \times (8 \times 8 \times 3)[/tex] will give her the total volume of the pans.

Step-by-step explanation:

Given: Length = 8 inch

Width = 8 inch

Height = 8 inch

Formula to calculate the volume of rectangular pans is as follows.

[tex]Volume = length \times width \times height\\[/tex]

Substitute the values into above formula as follows.

[tex]Volume = length \times width \times height\\= 8 \times 8 \times 3 in^{3}\\= 192 in^{3}[/tex]

Therefore, volume of each pan is 192 cubic inch. As there are three baking pans so total volume of the pans is as follows.

[tex]3 \times 192 in^{3}\\= 576 in^{3}[/tex]

Thus, we can conclude that an expression [tex]3 \times (8 \times 8 \times 3)[/tex] will give her the total volume of the pans.

Answer:

128

Step-by-step explanation:

I did the math

Answer:

it's 2 :)

Step-by-step explanation:

quotient is a term used in division so you divide

16 divided by 8 is 2 <3

don't forget to say thanks if you got it right ! :)

Answer:

y = ½x -3

Step-by-step explanation:

_____________________

Answer:

OH NO

Step-by-step explanation:

Step-by-step explanation:

oh srr, I'm Vietnamese and I don't know your

country's solution

but i think my answer is correct :((

Answer:

A.) m = 1.5 | B.) p = -1 | C.) t = 2

Step-by-step explanation:

A.)

[tex]4(m+3)=18\\4m+12=18\\4m=6\\m=3/2=1.5[/tex]

B.)

[tex]-2(p+5)+8=0\\-2p-10+8=0\\-2p-2=0\\-2p=2\\p=-1[/tex]

C.)

[tex]3+5(t-1)=8\\3+5t-5=8\\5t-2=8\\5t=10\\t=2[/tex]

Answer:

(a)=

4(m+3)=18

4m+12=18

4m=18-12

4m=6

m=

[tex] \frac{6}{4} [/tex]

(b)=

-2(p+5)+8=0

-2p-10+8=0

-2p=0+10-8

-2p=2

p=

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

(c)=

3+5(t-1)=8

3+5t-5=8

5t=8-3+5

5t=10

t=

[tex] \frac{10}{5} = 2[/tex]

[tex]please \: mark \: as \: brainliest \: because \: i \: spent \: much \: time \: on \: this \: question[/tex]

Answer:

4

Step-by-step explanation:

Answer:

[tex]n = \frac{20}{7}[/tex]

Step-by-step explanation:

[tex]4n + 5 = 25 - 3n\\4n + 3n = 25 - 5 \\7n = 20\\\\n = \frac{20}{7}[/tex]

Answer:

n = 20/7

Step-by-step explanation:

4n+5=25-3n

Add 3n to each side

4n+3n+5=25-3n+3n

7n +5 = 25

Subtract 5 from each side

7n+5-5=25-5

7n = 20

Divide by 7

7n/7 = 20/7

n = 20/7

Complete Question:

There are 750 spectator in the stadium of which 420 are women and the rest are men. What percent of the spectators are women?

Answer:

Percentage = 56%

Step-by-step explanation:

Given the following data;

Total number of people = 750

Number of women = 420

To find the percentage of women;

First of all, we would determine the number of male spectators (men);

Number of men = Total number of people - Number of women

Number of men = 750 - 420

Number of men = 330

Next, we find the percentage of women;

[tex] Percentage = \frac {420}{750} * 100 [/tex]

[tex] Percentage = \frac {42}{75} * 100 [/tex]

[tex] Percentage = 0.56 * 100 [/tex]

Percentage = 56%

Therefore, the percentage of the spectators that are women is 56%.

Answer:

x = 6, y = -8

Step-by-step explanation:

First we take the equations side by side and put them like this:

 6x + 2y = 16

+ 2x - 2y = 32

8x = 48

Then solve for x.

x = 6

Then insert x back into either equation

2(5) - 2y = 32

10 - 2y = 32

solve for y,

y = -10

Answer:

452.4 in³

Step-by-step explanation:

Volume half sphere = 1/2 volume sphere

Volume sphere = 4/3πr²

Volume = 4/3*3.14*27             Radius = 1/2(6) .     3³ = 27

Volume ≈ 113.1

Volume Cylinder = Area circle x hieght

Area circle = πr²

Area circle = 3.14 * 9

Area circle = 28.26

Volume cylinder = 28.26 * 12 = 339.12

339.12 + 113.1 = 452.22

Because of rounding it would be ≈ 452.4

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

Answer:

2/23

Hope this helps!

Answer:

domain: all real numbers

range: {y | y ≥ 0}

Answer:

260.

because 263 is below 265 so it wont change to 270.

Answer:

Step-by-step explanation:

A circle centered in [tex]P(x_o,y_o)[/tex] an radius [tex]r[/tex] has a equation:

[tex](x-x_o)^2+(y-y_o)^2=r^2[/tex]

So, your equation wold be:

[tex](x-0)^2+(y-0)^2=8^2\Rightarrow x^2+y^2=64[/tex]

The correct circle's equation with radius 8 is,

⇒ x² + y² = 64

The circle is a closed two dimensional figure , in which the set of all points is equidistance from the center.

Given that;

This circle is centered at the origin, and the length of its radius is 8.

Since, The general equation of circle with center (h, k) and radius r is,

⇒ (x - h)² + (y - k)² = r²

Here, Center = (0, 0)

Radius = 8

Hence, The correct circle's equation with radius 8 is,

⇒ (x - h)² + (y - k)² = r²

⇒ (x - 0)² + (y - 0)² = 8²

⇒ x² + y² = 64

Thus, The correct circle's equation with radius 8 is,

⇒ x² + y² = 64

Learn more about the circle visit:

https://brainly.com/question/24810873

#SPJ7

Answer: A polygon with 23 sides has a total of 3780 degrees. total interior angles = (n - 2)180°, where n is the number of sides.

The measure of one interior angle of the given regular polygon with 23 sides is 164.3 degrees

The formula which is used to calculate the sum of the angle of regular polygon is given by

sum of the interior angles = ( n - 2 ) × 180 degrees

Where,

n is the number of sides

According to the given question.

We have a regular polygon with 23 sides.

⇒ n = 23

Therefore,

The sum of the interior angles of the given regular polygon

= (23-2) × 180

= 3,780 degrees

So, the measure of one interior angle = [tex]\frac{3780}{23} = 164.3 degrees[/tex]

Hence, the measure of one interior angle of the given regular polygon with 23 sides is 164.3 degrees.

Find out more information about interior angle of a regular polygon here:

https://brainly.com/question/22408868

#SPJ3

Answer: 26.4

Step-by-step explanation: 1.2x22=

Answer:

a) Q(-2,1) is false

b) Q(-5,2) is false

c)Q(3,8) is true

d)Q(9,10) is true

Step-by-step explanation:

Given data is [tex]Q(x,y)[/tex] is predicate that [tex]x<y[/tex] then [tex]x^{2} <y^{2}[/tex]. where [tex]x,y[/tex] are rational numbers.

a)

when [tex]x=-2, y=1[/tex]

Here [tex]-2<1[/tex] that is [tex]x<y[/tex]  satisfied. Then

[tex](-2)^{2}<1^{2}[/tex]

[tex]4<1[/tex] this is wrong. since [tex]4>1[/tex]

That is [tex]x^{2}[/tex][tex]>y^{2}[/tex] Thus [tex]Q(x,y)[/tex] [tex]=Q(-2,1)[/tex]is false.

b)

Assume [tex]Q(x,y)=Q(-5,2)[/tex].

That is [tex]x=-5, y=2[/tex]

Here [tex]-5<2[/tex] that is [tex]x<y[/tex] this condition is satisfied.

Then

[tex](-5)^{2}<2^{2}[/tex]

[tex]25<4[/tex] this is not true. since [tex]25>4[/tex].

This is similar to the truth value of part (a).

Since in both [tex]x<y[/tex] satisfied and [tex]x^{2} >y^{2}[/tex] for both the points.

c)

if [tex]Q(x,y)=Q(3,8)[/tex] that is [tex]x=3[/tex] and [tex]y=8[/tex]

Here [tex]3<8[/tex] this satisfies the condition [tex]x<y[/tex].

Then [tex]3^{2} <8^{2}[/tex]

[tex]9<64[/tex] This also satisfies the condition [tex]x^{2} <y^{2}[/tex].

Hence [tex]Q(3,8)[/tex] exists and it is true.

d)

Assume [tex]Q(x,y)=Q(9,10)[/tex]

Here [tex]9<10[/tex] satisfies the condition [tex]x<y[/tex]

Then [tex]9^{2}<10^{2}[/tex]

[tex]81<100[/tex] satisfies the condition [tex]x^{2} <y^{2}[/tex].

Thus, [tex]Q(9,10)[/tex] point exists and it is true. This satisfies the same values as in part (c)

Answer:

1553.6mm

Step-by-step explanation:

Given data

Diameter = 622mm

Radius= 622/2= 311mm

Circumference= 2πr

Circumference= 2*3.142*311

Circumference= 1954.32

Each revolution the wheels will turn 1954.32mm

Now let us convert radian to turns

1 radian= 0.159155 turns

5 radians=  x turns

cross multiply

x= 5*0.159155

x=0.795 turns

If 1 turn will give 1954.32mm

0.795 turn will give  x

cross multiply

x= 0.795*1954.32

x=1553.6mm

Answer:

√16×81 = 4×9 or √1296 = 36

√16×√81 = 4×9 = 36

Step-by-step explanation:

√81×16

We simplify 81 and 16 by prime factorisation (expressing a number as a product of its prime factors).

√81 = √3×3×3×3 = √9×9 = √9² = 9

√16 = √2×2×2×2 = √4×4 = √4² = 4

Answer:

x = 57°

Step-by-step explanation:

Cos(x) = 0.5505

x = Cos⁻¹(0.5505)

x = 56.59

Rounding to the nearest degree;

x = 57°

Hope this helps!