A rectangle has perimeter 56 cm and length 21 cm. What is its width?

Answer:

Step-by-step explanation:

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Answer:

The aspect ratio represents the ratio of the width to the height of a television.  

The size of a TV is calculated using Pythagoras theorem. Assume the length ratio of the older 25-inch [tex]4:3[/tex] TV is x.

The ratio is represented as:

[tex]Width : Height = 4:3[/tex]

Using Pythagoras theorem, we have:

[tex]Width^2 + Height^2 = 25^2[/tex]

[tex](4x)^2 + (3x)^2 = 25^2[/tex]

[tex]16x^2 + 9x^2 = 625[/tex]

[tex]25x^2 = 625[/tex]

Divide both sides by 25

[tex]x^2 = 25[/tex]

Take positive square roots

[tex]x = 5[/tex]

So, the height of the image is:

[tex]Height = 3x[/tex]

[tex]Height = 3 \times 5 = 15[/tex]

While the width is

[tex]Width = 4x = 4 \times 5 = 20[/tex]

Hence, the height of the image is 15 inches

The height of each black bar is calculated as follows:

[tex]Width : Height = 2.35 : 1[/tex]

Where

[tex]Width = 20[/tex]

So, we have:

[tex]20 : Height = 2.35 : 1[/tex]

Express as fraction

[tex]\frac{Height}{20} = \frac{1}{2.35}[/tex]

Make Height the subject

[tex]Height = \frac{20}{2.35}[/tex]

[tex]Height = 8.51[/tex]

The height of each black bar at the top and at the bottom is 8.51 inches

The percentage of the screen’s area that is occupied by the image is calculated using

[tex]\% Screen = \frac{A_1}{A_2} \times 100\%[/tex]

Where

[tex]A_1 \to[/tex] Area of black bars

[tex]A_2 \to[/tex] Area of the 25-inch 4:3 television

So, we have:

[tex]A_1 =8.51 \times 20 = 170.2[/tex]

[tex]A_2 =15 \times 20 = 300[/tex]

[tex]\% Screen = \frac{A_1}{A_2} \times 100\%[/tex] becomes

[tex]\% Screen = \frac{170.2}{300} \times 100\%[/tex]

[tex]\% Screen = \frac{170.2}{3} \%[/tex]

[tex]\% Screen = 56.73 \%[/tex]

Hence, the percentage of the screen area occupied is 56.73%

Consumers moved to TV with a wide screen because a TV with wide screen shows bigger pictures than smaller dimension TV screens,

When the pictures are bigger, the consumers will have a clearer view of what they're watching.

Read more about aspect ratios at:

brainly.com/question/17231027

Answer:

ab = 144

Step-by-step explanation:

Assuming you mean a² + b² = 612, then

(a + b)² = a² + 2ab + b² , that is

30² = a² + 2ab + b²  , so

a² + 2ab + b² = 900

a² + b² + 2ab = 900 ← substitute a² + b² = 612

612 + 2ab = 900 ( subtract 612 from both sides )

2ab = 288 ( divide both sides by 2 )

ab = 144

Answer:

64[tex]\pi[/tex]

Step-by-step explanation:

A=[tex]\pi r^{2}[/tex]

Divide 16 by two to get the diameter: 8

Square 8: 64

Since the answer is in terms of pi, the answer is 64[tex]\pi[/tex]

Answer:

64 π

Step-by-step explanation:

Diameter = 16 inches

Radius = 16/2 = 8 inches

Area of circle = πr²

                      =  π(8)²

                      = 64 π sq inches

Answer:

500 - 6r = t

Step-by-step explanation:

500 represents the amount of copper wire Lisa started with.

-6r represents how much copper wire (in yards) is used on the robot (9*2 / 3 = 6).

t represents the total wire left after Lisa builds r robots.

Answer:

6

Step-by-step explanation:

The zeroes after the comma/full stop are significant...providede there is a non zero value in from of them just like the question posted

another example is 2300>>4significant digits or 0.00678 which has 3 significant digits.

hope this makes sense

:)

We have an algebra problem. Here we want to find the mid-value between 25.9 acres and 26 acres, we will find that the area of the compound is 25.95 acres.

For two given numbers A and B, such that A < B, the mid-value between these is given by:

A + (B - A)/2.

In this case, our two numbers are 25.9 and 26.

Using the above formula we get:

25.9 + (26 - 25.9)/2 =  25.95

Then we can conclude that the area of the compound is 25.95 acres.

If you want to learn more, you can read:

https://brainly.com/question/16871453

Answer:

C

Step-by-step explanation:

There are two arcs a major and a minor arc. You should never have to rely on a diagram to get the right answer.

The circumference is 2 * pi * r

r = 6 km

C = 2* pi * 6

C = 12 pi

The arc size is

arc size = 135 / 360 * 12pi

arc size = 3/8 * 12 pi

arc size = 4 1/2 pi = 9 pi /2  km

Answer:

-35 and 7

Step-by-step explanation:

7 - 35 = -28

35 has a (-) sign, and 7 has a (+) sign

Addition can be defined as the process of adding two numbers. The two integers with different signs that have a sum of -28 are -29 and 1.

Addition can be defined as the process of adding two numbers such that the result is the combined value of the two numbers.

An integer is a number that can be written without using a fractional component.

Given that the two integers with different signs have a sum of -28. Therefore, we can write,

Hence, the two integers with different signs that have a sum of -28 are -29 and 1.

Learn more about Addition here:

https://brainly.com/question/13167637

#SPJ2

Answer:

I am sorry I not no

this question

Step-by-step explanation:

sorry dear friend

Answer:

4x-2y =42 is the required equation

Step-by-step explanation:

given equation is,

4x-2y -7=0---------eqn1

parallel equation of given equation is

4x -2y+k =0-------eqn 2

now passing it through (9,-3), we get,

4×9 + 2×3 +k = 0

or,36+6+k =0

or,42+k =0

or, k= -42

putting the value of k in eqn2

4x-2y - 42=0

4x-2y = 42

Answer:

c=sqrt21

Step-by-step explanation:

angle c is the angle between a and b, so use the cos law

c^2=a^2+b^2-2*a*b*cosC

c^2= 16+25-2*4*5*1/2

c^2=21

c=sqrt21

Answer:

math question? u can ask on

Answer:

KL=63

Step-by-step explanation:

Answer:

Step-by-step explanation:

Kl=63

Answer:

[tex] \frac{ {12}^{8} }{ {12}^{4} } \\ = \frac{ {12}^{4} \times {12}^{4} }{ {12}^{4} } \\ = {12}^{4} =20736 \\ thank \: you[/tex]

Here's the solution :

[tex] \hookrightarrow \dfrac{12 {}^{8} }{ {12}^{4} } [/tex]

[tex] \hookrightarrow 12 {}^{8} \times {12}^{ - 4} [/tex]

[tex] \hookrightarrow12 {}^{4} [/tex]

Answer:

x = 8

Step-by-step explanation:

A common pythagorean triplet is 7, 8, 9

Answer:

11.4

Step-by-step explanation:

Pythagorean theorem

[tex]7^{2}[/tex] + [tex]9^{2}[/tex] = [tex]x^{2}[/tex]

49 + 81 = [tex]x^{2}[/tex]

130 = [tex]x^{2}[/tex]

11.4 = x

Answer:

[tex]f'(x)=1+\ln x[/tex]

Step-by-step explanation:

[tex]f'(x)[/tex] is notation for the first derivative of [tex]f(x)[/tex].

Recall the product rule:

[tex](f\cdot g)'=f'\cdot g+g'\cdot f[/tex]

Therefore, we have:

[tex]\displaystyle \frac{d}{dx}(x\ln x)=\frac{d}{dx}(x)\cdot \ln(x)+\frac{d}{dx}(\ln x)\cdot x[/tex]

Note that:

[tex]\displaystyle \frac{d}{dx}(x)=1,\\\\\frac{d}{dx}(\ln x)=\frac{1}{x}[/tex]

Simplify:

[tex]\displaystyle \frac{d}{dx}(x\ln x)=1\cdot \ln x+\frac{1}{x}\cdot x, \\\\\frac{d}{dx}(x\ln x)= \ln x+1=\boxed{1+\ln x}[/tex]

The derivative is:

[tex] \bold{f(x) \: = \: x \: \times \: (In(x))}[/tex]

[tex] \bold{f'(x) \: = \: \frac{d}{dx} (x \: \times \: In(x))}[/tex]

[tex] \bold{f'(x) \: = \: \frac{d}{dx} (x) \: \times \: In(x) \: + \: x \: \times \: \frac{d}{dx} (In(x))}[/tex]

[tex] \bold{f'(x) \: = \: 1In(x) \: + \: x \: \times \frac{1}{x} }[/tex]

[tex] \bold{f'(x) \: = \: In(x) \: + \: x \: \times \: \frac{1}{x} }[/tex]

[tex] \boxed{ \bold{f'(x) \: = \: In(x) \: + \: 1}}[/tex]

Step-by-step explanation:

[tex]275 \times 5 = 1375 [/tex]

The rate of the motorboat on still water is 1375

[tex]405 \times 5 = 2025[/tex]

The current rate of the motorboat is 2025

Answer:

7, 3, 0, -3, -5, -8, -14

Step-by-step explanation:

I know 7 is the greatest value you add the most because to get to 7 from 0.

I know -14 is the least value because I subtracted the most to get to -14 from 0.

Answer:

1

Step-by-step explanation:

The second power and square root cancel each other (second power means squared by the way)

Answer:

x = 2

Step-by-step explanation:

26-4x=9x

Add 4x to each side

26-4x+4x=9x+4x

26 = 13x

Divide each side by 13

26/13 = 13x/13

2 = x

Answer:

-26/5

Step-by-step explanation:

[tex]26 - 4x = 9x \\ 4x = 9x - 26 \\ - 5x = - 26 \\ \frac{ - 5x}{5} = \frac{26}{5} [/tex]

Answer:

0.72 repeat

Step-by-step explanation:

              __

8 ÷ 11 =0.72

Explanation:

We follow PEMDAS in reverse to undo every operation that is applied to variable x

Doing so will lead to the following

t = 0.4x + c

t - c = 0.4x

0.4x = t - c

x = (t - c)/(0.4)

The last equation is the same as writing [tex]x = \frac{t-c}{0.4}[/tex] which is what choice B shows.

Answer:

Yes it can be be the reflected figure

Answer:

In 4 months, they will both have 132 stamps.

Step-by-step explanation:

Let x = # of months

52 + 20x = 68 + 16x

4x = 16

x = 4

Plug x value into both expressions and see if it checks out

52 + 20(4) = 68 + 16(4)

52 + 80 = 68 + 64

132 = 132

Answer:

Surface area=48 in^2

See the image for solution

The shaded region of a circle formed by one line as shown in the image is called a segment.

Answer: segment

Answer:

12 hours

Step-by-step explanation:

each worker digs a hole and takes 4 hours doing so

2 workers dig 3 holes each, 3*4=12, 12 hours

Answer:

12 hours

Step-by-step explanation:

4 workers can dig 4 holes in hours=4

1   worker    ,,     ,,   4    ,,      ,,    ,,     =4×4=16

1      ,,           ,,     ,,    1   hole ,,    ,,     =16÷4=4

2     ,,           ,,     ,,    1     ,,     ,,    ,,    =4÷2=2

2     ,,           ,,     ,,    6 holes ,,    ,,    =2×6=12