Tại sao số mắt xích không được là bội số của số răng đĩa xích

Answer:

The unknown is 100

Step-by-step explanation:

A straight line is 180 degrees

We have two angles x, and 80

x+80 = 180

x = 180-80

x= 100

Answer:

the Si unit of temprature in Kelvin (K)

Step-by-step explanation:

Answer:

The answer is Kelvin (k).

Step-by-step explanation:

The kelvin (K) is defined by taking the fixed numerical value of the Boltzmann constant k to be [tex]1.380649*10^{-23}[/tex] when expressed in the unit of joule per kelvin. The temperature 0 K is commonly referred to as "absolute zero." On the widely used Celsius temperature scale, water freezes at 0 °C and boils at about 100 °C. One Celsius degree is an interval of 1 K, and zero degrees Celsius is 273.15 K. An interval of one Celsius degree corresponds to an interval of 1.8 Fahrenheit degrees on the Fahrenheit temperature scale.

The kelvin is also the fundamental unit of the Kelvin scale, an absolute temperature scale named for the British physicist William Thomson (known as Lord Kelvin). An absolute temperature scale has as its zero point absolute zero (−273.15° on the Celsius temperature scale and −459.67° on the Fahrenheit temperature scale), the theoretical temperature at which the molecules of a substance have the lowest energy; hence, all values on such a scale are nonnegative.  

You're looking for a solution of the form

[tex]\displaystyle y = \sum_{n=0}^\infty a_n x^n[/tex]

Differentiating twice yields

[tex]\displaystyle y' = \sum_{n=0}^\infty n a_n x^{n-1} = \sum_{n=0}^\infty (n+1) a_{n+1} x^n[/tex]

[tex]\displaystyle y'' = \sum_{n=0}^\infty n(n-1) a_n x^{n-2} = \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n[/tex]

Substitute these series into the DE:

[tex]\displaystyle (x-1) \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n - x \sum_{n=0}^\infty (n+1) a_{n+1} x^n + \sum_{n=0}^\infty a_n x^n = 0[/tex]

[tex]\displaystyle \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^{n+1} - \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n \\\\ \ldots \ldots \ldots - \sum_{n=0}^\infty (n+1) a_{n+1} x^{n+1} + \sum_{n=0}^\infty a_n x^n = 0[/tex]

[tex]\displaystyle \sum_{n=1}^\infty n(n+1) a_{n+1} x^n - \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n \\\\ \ldots \ldots \ldots - \sum_{n=1}^\infty n a_n x^n + \sum_{n=0}^\infty a_n x^n = 0[/tex]

Two of these series start with a linear term, while the other two start with a constant. Remove the constant terms of the latter two series, then condense the remaining series into one:

[tex]\displaystyle a_0-2a_2 + \sum_{n=1}^\infty \bigg(n(n+1)a_{n+1}-(n+1)(n+2)a_{n+2}-na_n+a_n\bigg) x^n = 0[/tex]

which indicates that the coefficients in the series solution are governed by the recurrence,

[tex]\begin{cases}y(0)=a_0 = -7\\y'(0)=a_1 = 3\\(n+1)(n+2)a_{n+2}-n(n+1)a_{n+1}+(n-1)a_n=0&\text{for }n\ge0\end{cases}[/tex]

Use the recurrence to get the first few coefficients:

[tex]\{a_n\}_{n\ge0} = \left\{-7,3,-\dfrac72,-\dfrac76,-\dfrac7{24},-\dfrac7{120},\ldots\right\}[/tex]

You might recognize that each coefficient in the n-th position of the list (starting at n = 0) involving a factor of -7 has a denominator resembling a factorial. Indeed,

-7 = -7/0!

-7/2 = -7/2!

-7/6 = -7/3!

and so on, with only the coefficient in the n = 1 position being the odd one out. So we have

[tex]\displaystyle y = \sum_{n=0}^\infty a_n x^n \\\\ y = -\frac7{0!} + 3x - \frac7{2!}x^2 - \frac7{3!}x^3 - \frac7{4!}x^4 + \cdots[/tex]

which looks a lot like the power series expansion for -7eˣ.

Fortunately, we can rewrite the linear term as

3x = 10x - 7x = 10x - 7/1! x

and in doing so, we can condense this solution to

[tex]\displaystyle y = 10x -\frac7{0!} - \frac7{1!}x - \frac7{2!}x^2 - \frac7{3!}x^3 - \frac7{4!}x^4 + \cdots \\\\ \boxed{y = 10x - 7e^x}[/tex]

Just to confirm this solution is valid: we have

y = 10x - 7eˣ   ==>   y (0) = 0 - 7 = -7

y' = 10 - 7eˣ   ==>   y' (0) = 10 - 7 = 3

y'' = -7eˣ

and substituting into the DE gives

-7eˣ (x - 1) - x (10 - 7eˣ ) + (10x - 7eˣ ) = 0

as required.

Answer:

Step-by-step explanation:

[tex]p(\overline{X}-\sigma \leq X \leq \overline{X}+\sigma)\\\\=p(\dfrac{\overline{X}-\sigma -\overline{X} }{\sigma} \leq Z \leq \dfrac{\overline{X}+\sigma -\overline{X} }{\sigma} )\\\\=p ( -1 \leq Z \leq 1)\\\\=2*(\ p (Z \leq 1)-0.5)\\\\=2*(0.8413-0.5)\\\\=0.6826\\\\\approx{68\%}[/tex]

Answer:

18c^3d^9

Step-by-step explanation:

2c^3 d^2 * 9d^7

We know that  we add the exponents when the base is the same

2*9  c^3 d^(2+7)

18c^3d^9

Answer:

General Educational Development (GED) tests

What do subject do you need help?

Step-by-step explanation:

The GED® exam is made up of 4 subjects, broken into separate exams: Mathematical Reasoning, Reasoning Through Language Arts, Social Studies, and Science.

Answer: r = 50 miles/h

Step-by-step explanation:

Let r be the rate of average speed.

Then

r = D/t

r = 150/3

r = 50 miles/h

please click thanks and mark brainliest if you like :)

The solution is 4ln3 - 3ln5, which is correct option(C).

There are four basic properties of logarithms:

logₐ(xy) = logₐx + logₐy.

logₐ(x/y) = logₐx - logₐy.

logₐ(xⁿ) = n logₐx.

logₐx = logₓa / logₓb.

Arithmetic operations can also be specified by the subtract, divide, and multiply built-in functions.

The operator that perform arithmatic operation are called arithmatic operators .

Operators which let do basic mathematical calculation

+ Addition operation : Adds values on either side of the operator.

For example 4 + 2 = 6

- Subtraction operation : Subtracts right hand operand from left hand operand.

for example 4 -2 = 2

* Multiplication operation : Multiplies values on either side of the operator

For example 4*2 = 8

/ Division operation : Divides left hand operand by right hand operand

For example 4/2 = 2

According to the problem, we will use some of the basic logarithmic properties,

Given expression,

⇒ ln81/125

⇒ ln81 - ln125   [used property : logₐ(x/y) = logₐx - logₐy]

⇒ ln3⁴ - ln5³    [ 81 =3⁴ and 125 = 5³ ]

⇒ 4ln3 - 3ln5   [used property : logₐ(xⁿ) = nlogₐx]

Hence, the solution is 4ln3 - 3ln5

Learn more logarithmic properties here:

brainly.com/question/24211708

#SPJ2

Answer:

Two numbers differ by 9 and the sum of their square is 653. What are the numbers?

Well,that's a mathematical question from algebra and it's quite difficult to answer such questions by writing through the circumstances offered by apps like quora.

However,I have tried to answer your question in an understandable way.Hope you may not find it difficult to analyze.

Let the numbers be x and (9+x)

Therefore,according to given,

x^2 + (9+x)^2 =653

=>x^2 + (9)^2 + x^2 + 2×(9)×(x)=653 (Applying the formula of (a+b)^2)

=>x^2 + 81 + x^2 + 18x =653

=>2x^2 + 18x + (81-653)=0

=>2x^2 + 18x - 572=0

=>2x^2 + (44x - 26x) - 572=0

=>2x^2 + 44x - 26x - 572=0

=>2x(x + 22) - 26(x + 22)=0

=>(x + 22)(2x - 26)=0

But since the number can't be negative

Therefore, x=13

Hence,the required numbers are 13 and 22.

Step-by-step explanation:

in first hope you like it

Answer:

Option C is correct

Step-by-step explanation:

[tex]log( {10}^{3} )[/tex]

[tex]3 \: log \: (10)[/tex]

[tex]3×1[/tex]

[tex]3[/tex]

The three main log rules you'll encounter are

The first rule allows us to go from a log of some product, to a sum of two logs. In short, we go from product to sum. The second rule allows us to go from a quotient to a difference. Lastly, the third rule allows to go from an exponential to a product.

Here are examples of each rule being used (in the exact order they were given earlier).

----------------

Here's a slightly more complicated example where the log rules are used.

log(x^2y/z)

log(x^2y) - log(z)

log(x^2) + log(y) - log(z)

2*log(x) + log(y) - log(z)

Hopefully you can see which rules are being used for any given step. If not, then let me know and I'll go into more detail.

Solution :

a). The probability that the student will [tex]\text{correctly answer}[/tex] the 1st question after the 4th attempt.

P (correct in the 4th attempt)

= [tex]$(1-0.75)^3 \times 0.75$[/tex]

= 0.01171875

b). The probability that the student will [tex]\text{correctly answer}[/tex] 3 questions after 10 total attempts.

P( X = 3) for X = B in (n = 10, p = 0.75)

= [tex]$C(10,30) \times 0.75^3 \times 0.25^7$[/tex]

= 0.0031

c). The mean and the standard deviation for the number of attempts up to when the students gets all the questions correct is :

There are = 6 success, p = 0.75.

Therefore, this is a case of a negative binomial distribution.

[tex]$E(X)=\frac{k}{p}$[/tex]

         [tex]$=\frac{6}{0.75}$[/tex]

         = 8

So, [tex]$\sigma = \frac{\sqrt{k(1-p)}}{p}$[/tex]

     [tex]$\sigma = \frac{\sqrt{6(1-0.75)}}{0.75}$[/tex]

        = 1.6330

Answer:

a<5

Step-by-step explanation:

11-2a>1

-2a>1-11

-2a>-10

a<5

y=x²-10x-7

a>0 so we will be looking for minimum

x=-b/2a=10/2=5

y=25-50-7=-32

Answer: (5;32)

y=-4x²-8x+1

а<0 so we will be looking for maximum

х=-b/2a=8/-8=-1

у=4+8+1=13

Maximum point (-1;13)

9514 1404 393

Answer:

  $1790.99

Step-by-step explanation:

Given:

  $1625 is invested at an annual rate of 1.95% compounded quarterly for 5 years

Find:

  the ending balance

Solution:

The compound interest formula applies.

  FV = P(1 +r/n)^(nt) . . . Principal P at rate r for t years, compounded n per year

  FV = $1625(1 +0.0195/4)^(4·5) = $1625(1.004875^20) ≈ $1790.99

The account ending balance would be $1790.99.

9514 1404 393

Answer:

  $11,680.58

Step-by-step explanation:

Usually, I would say copy the example, using 70,000 instead of 55,000. However, the example you show has a couple of errors in it. You need to do what it says, not follow what it did.

__

The first 48,535 is taxed at 15%, so the tax is 0.15×48535 = 7280.25.

The next (70,000 -48,535) = 21,465 is taxed at 20.5%, so the tax is ...

  0.205×21,465 = 4400.325 ≈ 4400.33

The the total tax due on $70,000 is ...

  $7280.25 +4400.33 = $11,680.58 . . . . tax due on $70,000

_____

Additional comments

The example shown has a couple of errors. The tax on the excess amount is figured at 2.05%, not 20.5%, and the 132.53 value from that is shown as 132.23.

__

Any tax table like this one can be reduced to a set of simpler formulas. Here are the formulas for the brackets shown in your tax table.

  ≤ 48535 -- income × 0.15

  ≤ 97069 -- income × 0.205 -2669.425

  ≤ 150,473 -- income × 0.26 -8008.22

  ≤ 214,368 -- income × 0.29 -12,522.41

  > 214,368 -- income × 0.33 -21,097.13

In this case, the second row of this simpler table would give the tax on $70,000 as ...

  tax = 70,000 × 0.205 -2669.425

  tax = 14350 -2669.425 = 11680.575 ≈ 11,680.58 . . . same as above

Answer:

0.9332

Step-by-step explanation:

We are given that

Mean diameter, [tex]\mu=73[/tex]

Variance, [tex]\sigma^2=4[/tex]

We have to find the probability that the diameter of a selected bearing is less than 76.

Standard deviation, [tex]\sigma=\sqrt{variance}=\sqrt{4}=2[/tex]

[tex]P(x<76)=P(\frac{x-\mu}{\sigma}<\frac{76-73}{2})[/tex]

[tex]P(x<76)=P(Z<\frac{3}{2})[/tex]

Where [tex]Z=\frac{x-\mu}{\sigma}[/tex]

[tex]P(x<76)=P(Z<1.5)[/tex]

[tex]P(x<76)=0.9332[/tex]

Hence, the probability that the diameter of a selected bearing is less than 76=0.9332

Answer:

the answer would be (7,5)

Answer and Step-by-step explanation:

First, we need to set this equation equal to y, which means we need to get y by itself, and all other terms equal to y.

x = [tex]2y^2 + 1[/tex]

Subtract 1, then divide by 2 on both sides.

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

Now, take the square root of both sides.

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

We see that the value with the x (1) is positive, and that we have a square root function, which means the parabola would open to the right.

(If the x value was negative, the square root function's parabola would open to the left)

So, C (Right) is the correct answer.

#teamtrees #PAW (Plant And Water)

I hope this helps!

Answer:

18

Step-by-step explanation:

The diameter is equal to twice the length of the radius

So if the radius is 9 then the diameter is 9 * 2 = 18

Answer:

Slope is 5/2

y-intercept is 2

Step-by-step explanation:

Turn the equation into slope intercept form [ y = mx +  b ].

2y = 5x + 4

~Divide everything by 2

y = 5/2x + 2

Remember that in slope intercept form, m = slope and b = y-intercept.

Best of Luck!

Answer:

slope: 2.5

y-intercept: 2

Step-by-step explanation:

First isolate the y variable which changes the equation to y=2.5x+2

The equation of a line is mx + b where m is the slope and b and the

y-intercept. Leading us to conclude that 2.5 is the slope and 2 is the y-intercept.

Step-by-step explanation:

Right Triangles and the Pythagorean Theorem. The Pythagorean Theorem, a2+b2=c2, a 2 + b 2 = c 2 , can be used to find the length of any side of a right triangle.

This shape consists of two primary special triangles, 30-60-90 and 45-45-90.

the side with the 60° will be half of the hypotenuse because 30° is across from it.

the side with the 30° will be 5.5√3 because 60° is across from it, and any sides that has 60° across from it is associated with a √3.

x is 5.5√6 because any sides that is "below" the 45° angles are associated with a √2 times the side that's above the 45°

Answer:

384 cars

Step-by-step explanation:

To find the total number of spaces in the carpark, we must multiply the number of rows by how many cars they can accommodate:

34 ⋅ 40 = 1360

As you can see, we have 1360 total spaces. Since there are 976 cars parked, and we want to find out how many spaces are left, we have to subtract the amount of cars parked from the total spaces.

1360 - 976 = 384

Therefore, our answer is 384, specifically, 384 cars.

Answer:

384 cars.

Step-by-step explanation:

40 * 34 - 976

= 1360 - 976

= 384.

Answer:

D

Step-by-step explanation:

A is rather a strange choice. The tools are used as extensions of our  senses. That's all that technology has done. We still need to observe things for ourselves if we are to learn. I actually really do not know what this statement means. My answer reflects what I think is true. Our need to observe and think is not hindered.

B is never going to be true. We still have to test things out, even with the best tools that we have.

C: The exact opposite is true. Our knowledge of the universe has expanded beyond our belief with the better tools of technology that we have.

D: This is the opposite of C and is the answer.

Answer:

The answer is 155.

Step-by-step explanation:

We can find the remaining parts of the triangle angles.

Answer:

y = 25x + 40

Step-by-step explanation:

The electrician charges $25 per hour.

The number of hours is x.

Therefore after x hours the electrician will charge $25x. (multiply the charge by the number of hours $25 * x)

Therefore fee(y) charged by the electrician = $40 + $25x

Hence y = 25x + 40

Answer:

5%

Step-by-step explanation:

given,

Earns= Rs 640

spends= Rs 608

saves= (Rs 640 - Rs 608)

=Rs 32

therefore, 32/640x100

answer = 5%

Answer From Gauth Math

Answer:

5%

Step-by-step explanation:

save=640-608=32

(32/640)*100%

5%

Answer:

a) 120

b) 6

c) 1/20

Step-by-step explanation:

a) 5! = 120

b) (5 - 2)! = 6

c) 6/120 = 1/20