Determine the value of y, if x is-9.

Answer:

Statements Reasons

AB¯¯¯¯¯¯¯¯≅BC¯¯¯¯¯¯¯¯ Given

∠ADB and ∠CDB are right angles Given

ΔADB and ΔCDB are right triangles definition of right triangles

BD¯¯¯¯¯¯¯¯≅BD¯¯¯¯¯¯¯¯ reflexive property

ΔADB≅ΔCDB HL≅

AD¯¯¯¯¯¯¯¯≅DC¯¯¯¯¯¯¯¯ CPCTC (corresponding parts of congurent triangles must be congurent)

Step-by-step explanation:

Most of the geometry concepts and theorems that are learned in high school today were first discovered and proved by mathematicians such as Euclid thousands of years ago. Given that these geometry concepts and theorems have been known to be true for thousands of years, why is it important that you learn how to prove them for yourself?

Theorems and Proofs

In geometry, a postulate is a statement that is assumed to be true based on basic geometric principles. An example of a postulate is the statement “through any two points is exactly one line”. A long time ago, postulates were the ideas that were thought to be so obviously true they did not require a proof. A theorem is a mathematical statement that can and must be proven to be true. You've heard the word theorem before when you learned about the Pythagorean Theorem. Much of your future work in geometry will involve learning different theorems and proving they are true.

What does it mean to “prove” something? In the past you have often been asked to “justify your answer” or “explain your reasoning”. This is because it is important to be able to show your thinking to others so that ideally they can follow it and agree that you must be right. A proof is just a formal way of justifying your answer. In a proof your goal is to use given information and facts that everyone agrees are true to show that a new statement must also be true.

Suppose you are given the picture below and asked to prove that AD¯¯¯¯¯¯¯¯≅DC¯¯¯¯¯¯¯¯. This means that you need to give a convincing mathematical argument as to why the line segments MUST be congruent.

Here is an example of a paragraph-style proof. This is similar to a detailed explanation you might have given in the past.

AB¯¯¯¯¯¯¯¯≅BC¯¯¯¯¯¯¯¯ because it is marked in the diagram.  Also, ∠ADB and ∠CDB are both right angles because it is marked in the diagram.  This means that △ADB and △CDB are right triangles because right triangles are triangles with right angles.  Both triangles contain segment BD¯¯¯¯¯¯¯¯.  BD¯¯¯¯¯¯¯¯≅BD¯¯¯¯¯¯¯¯ because of the reflexive property that any segment is congruent to itself.  △ADB≅△CDB by HL≅ because they are right triangles with a pair of congruent legs and congruent hypotenuses.  AD¯¯¯¯¯¯¯¯≅DC¯¯¯¯¯¯¯¯ because they are corresponding segments and corresponding parts of congruent triangles must be congruent.

There are two key components of any proof -- statements and reasons.

The statements are the claims that you are making throughout your proof that lead to what you are ultimately trying to prove is true. Statements are written in red throughout the previous proof.

The reasons are the reasons you give for why the statements must be true. Reasons are written in blue throughout the previous proof. If you don't give reasons, your proof is not convincing and so is not complete.

When writing a proof, your job is to make everything as clear as possible, because you need other people to be able to understand and believe your proof. Skipping steps and using complicated words is not helpful!

There are many different styles for writing proofs. In American high schools, a style of proof called the two-column proof has traditionally been the most common (see Example 3). In college and beyond, paragraph proofs are common. An example of a style of proof that is more visual is a flow diagram proof (see Example 4). No matter what style is used, the key components of statements and reasons must be present. You should be familiar with different styles of proof, but ultimately can use whichever style you prefer.

Learning to write proofs can be difficult. One of the best ways to learn is to study examples to get a sense for what proofs look like.

Answer:

False

Step-by-step explanation:

It doesn't need to be proven in order to be used. We can just assume the postulate is true.

Answer:

Angle A always equal angles T

the first answer

Answer: sry i dont know

Step-by-step explanation:

Answer:

-1/2  

Step-by-step explanation:

first point is 1,-4

second point is 5,-6

Slope is  y2-y1/x2-x1

-6 - -4 / 5 - 1

-2/ 4

-1/2

Answer: 132.67 to the power of 2 (inches)

Step-by-step explanation:

The circumference of a circle is given as 2πr. Therefore, in his case,

2πr = 40.82

2 × 3.142 × r = 40.82

6.284r = 40.82

radius = 40.82/6.284

radius = 6.5 inches

Area will now be:

= πr²

= 3.142 × 6.5²

= 3.142 × 42.25

= 132.75 inches²

Therefore, the closest answer will be 132.67 to the power of 2 (inches).

Responder:

Teléfonos móviles :

Universo - -> {todos los teléfonos móviles} - unidad experimental

Población - -> {Samsung, tecno, LG, iPhone, Motorola, Huawei, .....} - -> valores variables de unidades experimentales

Muestra - - -> {Samsung, tecno, iPhone} - selección aleatoria de datos de población

Países europeos :

Universo - -> {todos europeos} - unidad experimental

Población - -> {Inglaterra, Noruega, Turquía, Italia, Francia, Holanda, .....} - -> valores variables de todos los países europeos

Muestra - - -> {España, Alemania, Polonia} - selección aleatoria a partir de datos de población

Explicación paso a paso:

Haciendo distinción entre universo, población y muestra. Univerae y la población se describen como sinónimos en algún texto. Sin embargo, otros textos estadísticos hicieron diferencias sutiles entre ambos; con el universo que se dice que contiene todas las unidades experimentales. ; siendo población el conjunto de valores de la variable. Sin embargo, podemos asumir de manera concluyente que ambos son sinónimos, ya que de ellos se extrae una muestra que es un subconjunto de un conjunto de datos más grande (población).

Answer:

ok let me help

Step-by-step explanation:

v=268.08 sooo

r(radius) which is 4

v=4/3 n r³ =4/3×n×4³ = 268.08

Answer:

(256/3)π or 85.33π

Step-by-step explanation:

The equation for volume of a sphere is 4/3πr^3 where r = the radius

So the volume of the sphere in terms of pi would be

4/3(π)(4)^3

(4/3)(64)π

4 x 64 = 256

256/3 = 85.33

In terms of pi the answer is (256/3)π or 85.33π

Answer:

f(5) = 22

Step-by-step explanation:

When we want to solve for f(x) = 5x - 3 when x is 5, all we have to do is plug in 5 as x into the equation.

f(x) = 5x - 3

f(5) = 5(5) - 3

5 * 5 = 25

25 - 3 = 22

f(5) = 22

I hope this helps you!

Answer:

23.56

Step-by-step explanation:

i thin if not then 13,67

Answer:

he should be in 11 inches

Answer:

No

Step-by-step explanation:

30% is the same as 3/10

3/7 is about the same as 43%  

There is a difference among the percentage so no it's not correct

Yes, the value 30% of 70 is the same as 3/7 of 70.

Expression in maths is defined as the relation of numbers variables and functions by using mathematical signs like addition, subtraction, multiplication, and division.

To show this mathematically, we can start by calculating 30% of 70:

30% of 70 = (30/100) x 70

= 0.3 x 70

= 21

Now, let's calculate 3/7 of 70:

3/7 of 70 = (3/7) x 70

= 30/100 x 70

= 0.3 x 70

= 21

As we can see, both calculations give us the same result of 21. Therefore, 30% of 70 is the same as 3/7 of 70.

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Answer:

1360

Step-by-step explanation:

I know because I get all a's but then again I might be wrong I  didn't take my time so sorry  

Answer:

x = 110°

Step-by-step explanation:

∠ QRS = ∠ YRT = 110° ( vertically opposite angles )

∠ PQR = 180° - 120° = 60° ( adjacent angles )

The sum of the interior angles of a quadrilateral = 360°

Sum the angles and equate to 360°, that is

110 + 60 + x + 80 = 360

250° + x = 360° ( subtract 250° from both sides )

x = 110°

Answer:

(a) [tex]P(x) = 1342.7x + 64792[/tex]

(b) [tex]P(60) = 145354[/tex]

(c) [tex]P(x) = 64792 *1.0175^x[/tex]

(d) [tex]P(60) = 183491[/tex]

(e) The exponential model is more realistic

Step-by-step explanation:

Given

[tex]1990 ==> P_0 =64792[/tex]

[tex]2010 ==> P_{20} =91646[/tex]

Solving (a): The linear model of the population growth

First, we calculate the slope of the function.

[tex]m = \frac{P_{20} - P_0}{20 - 0}[/tex]

[tex]m = \frac{91646 - 64792}{20 - 0}[/tex]

[tex]m = \frac{26854}{20}[/tex]

[tex]m = 1342.7[/tex]

The linear equation is then calculated using:

[tex]P(x) - P_0 = m(x - x_0)[/tex]

[tex]P(x) - 64792 = 1342.7(x - 0)[/tex]

[tex]P(x) - 64792 = 1342.7(x)[/tex]

[tex]P(x) - 64792 = 1342.7x[/tex]

Make P(x) the subject

[tex]P(x) = 1342.7x + 64792[/tex]

Solving (b): The population in 2050

First, calculate x:

[tex]x = 2050 - 1990[/tex]

[tex]x = 60[/tex]

Substitute 60 for x in [tex]P(x) = 1342.7x + 64792[/tex]

[tex]P(60) = 1342.7 * 60 + 64792[/tex]

[tex]P(60) = 80562 + 64792[/tex]

[tex]P(60) = 145354[/tex]

The population in 2050 is 145354

Solving (c): The exponential model of the population growth

An exponential model is:

[tex]y = ab^x[/tex]

In this case, it is:

[tex]P(x) = P_0 * b^x[/tex]

For x = 20, we have:

[tex]P(20) = P_0 * b^{20[/tex]

Substitute values for P(20) and P0

[tex]91646 = 64792 * b^{20[/tex]

Divide both sides by 64792

[tex]\frac{91646 }{64792} = \frac{64792 * b^{20}}{64792}[/tex]

[tex]\frac{91646 }{64792} = b^{20}[/tex]

[tex]1.41446474873 = b^{20}[/tex]

Take the 20th root of both sides

[tex]\sqrt[20]{1.41446474873} = b[/tex]

[tex]b = \sqrt[20]{1.41446474873}[/tex]

[tex]b = 1.0175[/tex]

So, the model is:

[tex]P(x) = P_0 * b^x[/tex]

[tex]P(x) = 64792 *1.0175^x[/tex]

Solving (d): The population in 2050

First, calculate x:

[tex]x = 2050 - 1990[/tex]

[tex]x = 60[/tex]

Substitute 60 for x in [tex]P(x) = 64792 *1.0175^x[/tex]

[tex]P(60) = 64792 *1.0175^{60[/tex]

[tex]P(60) = 64792 *2.832[/tex]

[tex]P(60) = 183490.944[/tex]

[tex]P(60) = 183491[/tex] ---- approximated

(e) The most realistic model

The exponential model is more realistic. This is so because:

The linear model grows at a constant linear rate which means that, every year a certain amount of individuals is added to the society. However, this is not always so because it is almost impossible to for growth rate to be constant

A curve in the exponential model shows that the addition of individuals in the society every year is not always constant.

Step-by-step explanation:

1) c

2) c

use the value of slope and the coordinates and substitute in the equation of line.

Answer:

$45

Step-by-step explanation:

17.95÷2 = 8.975

8.975 × 5 = 44.875

Round to $45

Answer:

$45

Step-by-step explanation:

17.95/2 would be 8.975

then 8.975 times 5 would be 44.875

rounding it to the dollar would be about 45 dollars

hope this helps

Answer:

6

Step-by-step explanation:

https://web2.0calc.com/questions/algebra_69756

Theodore get 6 quarters in Prize.

A branch of mathematics known as algebra deals with symbols and the mathematical operations performed on them.

Variables are the name given to these symbols because they lack set values.

In order to determine the values, these symbols are also subjected to various addition, subtraction, multiplication, and division arithmetic operations.

Given:

let p the number of pennies, d be the number of dimes, n be the number of nickels and q be number of quarters.

So, the expressions are

p = 3d                

n = d+1              

   = 5(d+1)

d = 10d

and, q = 2d              

           = 25 (2d)                    

and, the total is = $209

                          = 209

Then,

3d + 5(d+ 1)  + 10d  +25 ( 2d) = 209

68d + 5 = 209

d = 3                          

Thus, the number of quarters = 2d = 6 quarters.

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Answer:

5-2x

Step-by-step explanation:

Answer:

I think is is 14 square inches.

Step-by-step explanation:

2 plus 2 plus 5 plus 5 = 14

I don't know if this is right.

not times because 2 time 2 times 5 times 5 equals 100. there is no 100 . divide is not working and subtract is not working so add. I hoke this is correct and helps.

Answer:

38

Step-by-step explanation:

38 / -2 = -19

-19 + 7 = -12

Answer:

I love algebra anyways

The ans is in the picture with the  steps how i got it

(hope this helps can i plz have brainlist :D hehe)

Step-by-step explanation:

Answer:

sen türksün be ne işin var senin burada

Answer:

9x+15, and I used the distributive property

Step-by-step explanation:

Answer:

distributive property

9x+15

Step-by-step explanation:

The distributive property is whenever you have () and distribute until you have zero of these ()

The equivalent expression simply means write this equation differently.

Answer:

Step-by-step explanation:

(-2 - 2)/(-4 + 2)= -4/-2= 2 is the slope

y - 2 = 2(x + 2)

y - 2 = 2x + 4

y = 2x + 6 is the equation

Answer:

The slope is 2

Step-by-step explanation:

Hope this helps！

Answer:

x = 5.7           y = 9.4

m∠H = 31°

Step-by-step explanation:

cos of an angle = adjacent side/hypotenuse

and sine of an angle = opposite side/hypotenuse

cos 59 = x/11          and sin 59 = y/11

11 cos 59 = x                  11 sin 59 = y

x = 5.7                             y = 9.4

m∠H = 90 - 59 = 31°

You need  to memorize the definitions of all the trig functions and then these types of problems will be easy for you.

[tex]x=5.7[/tex], [tex]y=9.4[/tex]  and ∠[tex]H[/tex][tex]=31[/tex]° is the solution of the triangle.

What is trigonometric ratio?

Trigonometric ratios are the ratios of the length of sides of a triangle. These ratios in trigonometry relate the ratio of sides of a right triangle to the respective angle.

The basic trigonometric ratios formulas are given below :

sin θ = Perpendicular/Hypotenuse

cos θ = Base/Hypotenuse

tan θ = Perpendicular/Base

sec θ = Hypotenuse/Base

cosec θ = Hypotenuse/Perpendicular

cot θ = Base/Perpendicular

The sum of angles of a triangle equals the straight angle (180 degrees, π radians, two right angles, or a half-turn)

According to question,

In Δ FGH ,

∠G = 59°

Hypotenuse of triangle = 11

Base of triangle according to the ∠G = x

Perpendicular of triangle according to the ∠G = y

Now,

Cosθ =  [tex]\frac{Base}{Hypotenuse}[/tex]

[tex]Cos[/tex] 59° =  [tex]\frac{x}{11}[/tex]

   [tex]x[/tex] [tex]=11[/tex]× [tex]0.515[/tex]     (  Cos59° = [tex]0.515[/tex] )

     x [tex]=5.7[/tex]

Sinθ = [tex]\frac{Perpendicular}{Hypotenuse}[/tex]

[tex]Sin[/tex] [tex]59[/tex]° [tex]=\frac{y}{11}[/tex]

      [tex]y=11[/tex] * 0.857

       y [tex]=9.4[/tex]

According to the sum of angle of triangle

∠F + ∠G +∠H = 180°

90° + 59° + ∠H = 180°

∠H = 180° - 90 -59

∠H = 31°

Hence,[tex]x=5.7[/tex], [tex]y=9.4[/tex]  and ∠[tex]H[/tex][tex]=31[/tex]° is the solution of the triangle.

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Answer:

answer is c   because   of the y intercept  . . so the y intercept is postive and goes through the orgin

Step-by-step explanation:

Answer:

x = 21

Step-by-step explanation:

x : 6 = 7 : 2

x/6 = 7/2

x/6 = 21/6

x = 21

b. -10 each time

c. The height of the slide/ the height at the top of the slide

d. 6 seconds. when Kirk is on the ground ( 0 feet off the ground), 6 seconds have past. You can see this in the point (6,0)

Answer:

1.2+0.75=1.95 pounds

Step-by-step explanation:

Answer:

4

Step-by-step explanation:

78