It cost Josiah $9.75 to send 65 text messages. How many text messages did he send if
he spent $28.20?

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:

we have two equations:

2*x + y = 20

y = a + 18/x - 3

We want to find the values of a such that the graphs of the equations do not intersect.

The first step is to isolate y in the first equation.

now we get:

y = 20 - 2*x

Then we have the system of equations:

y = 20 - 2*x

y = a + 18/x - 3

If the line intersects the curve at a point (x, y), then at that point both functions have the same value of y, then:

20 - 2*x = y = a + 18/x- 3

We want to find a value of such that this does not happen.

Let's solve that equation and see what we can find.

20 - 2*x =  a + 18/x - 3

20 + 3 = a + 18/x + 2*x

23 = a + 18/x + 2*x

(23 - a) = 18/x + 2*x

if we multiply all values by x, we get:

(23 - a)*x = 18 + 2*x^2

Then we have a quadratic equation, we can write this as:

2*x^2 - (23 - a)*x + 18 = 0

Now, remember that if the determinant of the quadratic function is smaller than zero, then the function does not have any real solution, then we need to find a such that the determinant of this quadratic equation is smaller than zero.

Remember that for a quadratic equation:

a*x^2 + b*x + c = 0 is:

b^2 - 4*a*c

In this case, the determinant is:

(-(23 - a))^2 - 4*2*18

(23 - a)^2 - 144

And this must be smaller than zero, then:

(23 - a)^2 - 144 < 0

23^2 - 2*23*a + a^2 - 144 < 0

529 - 46*a + a^2 - 144 < 0

a^2 - 46*a + 385 < 0

Notice that the function has a positive leading coefficient, then the arms of the function go upwards, then the region of the function that is smaller than zero is the values of a that are between both roots of a.

Then we need to solve:

a^2 - 46*a + 385 = 0

We can use the Bhaskara's equation to find the roots, the roots are given by:

[tex]a = \frac{-(-46) +- \sqrt{(-46)^2 - 4*1*385} }{2*1} = \frac{46 +-24}{2}[/tex]

Then the two roots are:

a₁ = (46 + 24)/2 = 35

a₂ = (46 - 24)/2 = 11

Then for all the values of a suc that:

11 < a < 35

The line does not intersect the curve.

Answer:

1) unlikely   1/8   12.5%

2) equally likely   4/8   50%

3) likely  5/8    62.5%

4)impossible 0/10 0%

5) unlikely    3/8  37.5%

Answer:b

Step-by-step explanation:

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:

1. -3/2

2. 8

Step-by-step explanation:

Plug the number in with x to find the answer, then solve using PEMDAS as normal.

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:

1.2+0.75=1.95 pounds

Step-by-step explanation:

Answer:

1.41 x 10 to the 7th power

Step-by-step explanation:

3 x 10 to the fifth is 300000

300000 x 47 = 14100000 in 47 seconds

14100000 = 1.41 x 10 to the 7th power

Hope that helps!

Answer:

1.41*10^7 or 14,100,000

Step-by-step explanation:

3*10^5*47=1.41*10^7

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:

0.40m/s^2

Step-by-step explanation:

Given data

Mass= 133.5kg

Force F= 54.5N

The expression for the force acting is

F=ma

substitute

54.5=133.5*a

]Divide both sides by 133.5

a= 54.5/133.5

a= 0.40 m/s^2

Hence the acceleration is 0.40m/s^2

Step-by-step explanation:

1) c

2) c

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

Answer:

A

Step-by-step explanation:

another helluva boss meme

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:

38

Step-by-step explanation:

38 / -2 = -19

-19 + 7 = -12

Answer:

the answer is 4.54%

Answer:

Coefficient. For example, in the term -3x, -3 serves as the coefficient of x.

The number in front of a variable or term is called a coefficient.

The coefficient represents the numerical factor by which the variable or term is multiplied. In an algebraic expression, the coefficient is the number that appears directly in front of the variable.

For example, in the expression 5x, the coefficient of x is 5. Similarly, in the expression 3y², the coefficient of y² is 3. The coefficient helps determine the magnitude or scale of the variable or term within the expression.

Therefore, the number in front of a variable or term is called a coefficient.

Learn more about coefficients here:

https://brainly.com/question/14590592

#SPJ6

Answer:

he should be in 11 inches

Answer:

mira aveces el cereal se come con leche y aveces se come con yogurt a quienes lo hacen así claro el cereal tiene almidones

Answer:

x = 2

Step-by-step explanation:

CDEF is a parallelogram.

CE and FD are its diagonals.

Diagonals of a parallelogram bisects each other.

Therefore,

10x - 5 = 4x + 7

10x - 4x = 7 + 5

6x = 12

x = 12/6

x = 2

Thus, for x = 2, CDEF is a parallelogram.

In the quadrilateral CDEF, the value of x is 2.

Mathematical expression is defined as the collection of the numbers variables and functions by using operations like addition, subtraction, multiplication, and division.

Given that;

Quadrilateral CDEF is a parallelogram.

Here, CE and FD are its diagonals.

We know that;

Diagonals of a parallelogram bisects each other.

Therefore, We can formulate;

⇒ 4x + 7 = 10x - 5

Solve for x as;

⇒ 7 + 5 = 10x - 4x

⇒ 12 = 6x

⇒ x = 12/6

⇒ x = 2

Learn more about the mathematical expression visit:

brainly.com/question/1859113

#SPJ2

Answer:

23.56

Step-by-step explanation:

i thin if not then 13,67

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:

-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:

(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.

Answer:

164.64

Step-by-step explanation:

you just have to multiply

8.4 x 3.5= 29.4 then you do 29.4 x 5.6 = 164.64

Answer:

x = 21

Step-by-step explanation:

x : 6 = 7 : 2

x/6 = 7/2

x/6 = 21/6

x = 21

Answer:

4

Step-by-step explanation:

78

Answer:

20%

Step-by-step explanation:

12-10=2

changed ÷ original x 100

2 ÷ 10 x 100

=20%