: Một khu đất 20 ha người ta trồng hai loại cây ngô và khoai. Năng suất của ngô tính theo x ha được (5-x/4) tấn trên 1 ha và năng suất của khoai tính theo y ha được (7-y/4) tấn trên 1 ha. Xác định diện tích trồng từng loại cây để sản lượng thu được là lớn nhất.

The mean score for all 23 students is 77.17.

Mean is the average of a set of numbers. It is determined by adding the numbers together and dividing it by the total number.

The first step is to determine the total scores of the 22 students.

Total scores = mean score x number of students

22 x 76.5 = 1683

The second step is to add the score of the student that took the exam late tot he total scores.

New total score = 1683 + 92 = 1775

The third step is to determine the new mean score.

new mean score = new total score / total number of students

1775 / 23 = 77.17

To learn more about the mean of a set of numbers, please check: https://brainly.com/question/15420908?referrer=searchResults

Answer:

a) 34

b) 17

c)46

Step-by-step explanation:

55-21 = 34

count

Answer:

19. y=5x+-1

20. y=-2.5x+4

Step-by-step explanation:

19: 9-4=5

-1+5=4 so m=5

b=-1

so y=5x+-1

20: -1-1.5=-2.5

4+-2.5=1.5

so m=-2.5

b=4

so y= -2.5x+4

Please mark me brainliest

Answer: 28

Step-by-step explanation:

Answer:

4

Step-by-step explanation:

because the others are shown wrong in 2 there are 5 tally marks and in 10 there are 6 telly marks

Answer: i just did this and its 4

Step-by-step explanation:

im dum as fudge

Answer:

Step-by-step explanation:

Given numbers:

Put the numbers in ascending order:

Since the set is even, the median is the average of the middle numbers:

Answer:

  3

Step-by-step explanation:

5(9/12 -1/4) +0.5

= 5(9/12 -3/12) +1/2 . . . . . . express the fractions using a common denominator

= 5(6/12) +1/2 . . . . . . . add the fractions

= 5(1/2) +1/2 . . . . . . reduce the result

= (5 +1)(1/2) . . . . factor out 1/2 (easier than adding mixed numbers)

= 6/2 = 3

_____

A calculator can be a useful tool for evaluating numerical expressions.

Answer:

y = 19/36

Step-by-step explanation:

Assuming that what you want is the value of y, you can pass all the right side stuff to the left, and the y to the right:

2/3 + 15/6 = 6y

Then you can sum the fractions on the left by using the same denominators:

4/6 + 15/6 = 6y       ==>      19/6 = 6 * y

then  you can pass the 6 that is multiplying on the right to the left - now dividing:

y = 19/36

Answer:

  y = 5/12

Step-by-step explanation:

  2/3 - 6y = -1 5/6 . . . . . given

  4 -36y = -11 . . . . . . . . . multiply by 6

  15 = 36y . . . . . . . . . . add 36y+11

  15/36 = y = 5/12 . . . . divide by 36, reduce the fraction

_____

Check

  2/3 -6(5/12) = -1 5/6

  4/6 -15/6 = -11/6 . . . . true

Answer:

Answer below

Step-by-step explanation:

1/8 is correct

in pic

_________________________________________

(Hope this helps can I pls have brainlist (crown)☺️)

Answer:

y = 8x/93

Step-by-step explanation:

To get the find the inverse function, swap x and y and solve the equation for x.

1. The given equation is probably supposed to read

y'' - 2y' - 3y = 64x exp(-x)

First consider the homogeneous equation,

y'' - 2y' - 3y = 0

which has characteristic equation

r² - 2r - 3 = (r - 3) (r + 1) = 0

with roots r = 3 and r = -1. Then the characteristic solution is

[tex]y = C_1 e^{3x} + C_2 e^{-x}[/tex]

and we let y₁ = exp(3x) and y₂ = exp(-x), our fundamental solutions.

Now we use variation of parameters, which gives a particular solution of the form

[tex]y_p = u_1y_1 + u_2y_2[/tex]

where

[tex]\displaystyle u_1 = -\int \frac{64xe^{-x}y_2}{W(y_1,y_2)} \, dx[/tex]

[tex]\displaystyle u_2 = \int \frac{64xe^{-x}y_1}{W(y_1,y_2)} \, dx[/tex]

and W(y₁, y₂) is the Wronskian determinant of the two fundamental solutions. This is

[tex]W(y_1,y_2) = \begin{vmatrix}e^{3x} & e^{-x} \\ (e^{3x})' & (e^{-x})'\end{vmatrix} = \begin{vmatrix}e^{3x} & e^{-x} \\ 3e^{3x} & -e^{-x}\end{vmatrix} = -e^{2x} - 3e^{2x} = -4e^{2x}[/tex]

Then we find

[tex]\displaystyle u_1 = -\int \frac{64xe^{-x} \cdot e^{-x}}{-4e^{2x}} \, dx = 16 \int xe^{-4x} \, dx = -(4x + 1) e^{-4x}[/tex]

[tex]\displaystyle u_2 = \int \frac{64xe^{-x} \cdot e^{3x}}{-4e^{2x}} \, dx = -16 \int x \, dx = -8x^2[/tex]

so it follows that the particular solution is

[tex]y_p = -(4x+1)e^{-4x} \cdot e^{3x} - 8x^2\cdot e^{-x} = -(8x^2+4x+1)e^{-x}[/tex]

and so the general solution is

[tex]\boxed{y(x) = C_1 e^{3x} + C_2e^{-x} - (8x^2+4x+1) e^{-x}}[/tex]

2. I'll again assume there's typo in the equation, and that it should read

y''' - 6y'' + 11y' - 6y = 2x exp(-x)

Again, we consider the homogeneous equation,

y''' - 6y'' + 11y' - 6y = 0

and observe that the characteristic polynomial,

r³ - 6r² + 11r - 6

has coefficients that sum to 1 - 6 + 11 - 6 = 0, which immediately tells us that r = 1 is a root. Polynomial division and subsequent factoring yields

r³ - 6r² + 11r - 6 = (r - 1) (r² - 5r + 6) = (r - 1) (r - 2) (r - 3)

and from this we see the characteristic solution is

[tex]y_c = C_1 e^x + C_2 e^{2x} + C_3 e^{3x}[/tex]

For the particular solution, I'll use undetermined coefficients. We look for a solution of the form

[tex]y_p = (ax+b)e^{-x}[/tex]

whose first three derivatives are

[tex]{y_p}' = ae^{-x} - (ax+b)e^{-x} = (-ax+a-b)e^{-x}[/tex]

[tex]{y_p}'' = -ae^{-x} - (-ax+a-b)e^{-x} = (ax-2a+b)e^{-x}[/tex]

[tex]{y_p}''' = ae^{-x} - (ax-2a+b)e^{-x} = (-ax+3a-b)e^{-x}[/tex]

Substituting these into the equation gives

[tex](-ax+3a-b)e^{-x} - 6(ax-2a+b)e^{-x} + 11(-ax+a-b)e^{-x} - 6(ax+b)e^{-x} = 2xe^{-x}[/tex]

[tex](-ax+3a-b) - 6(ax-2a+b) + 11(-ax+a-b) - 6(ax+b) = 2x[/tex]

[tex]-24ax+26a-24b = 2x[/tex]

It follows that -24a = 2 and 26a - 24b = 0, so that a = -1/12 = -12/144 and b = -13/144, so the particular solution is

[tex]y_p = -\dfrac{12x+13}{144}e^{-x}[/tex]

and the general solution is

[tex]\boxed{y = C_1 e^x + C_2 e^{2x} + C_3 e^{3x} - \dfrac{12x+13}{144} e^{-x}}[/tex]

Answer:

No

Step-by-step explanation:

yes it is

for it to not be a function it would need to have a curve or somthing that make it go somehwere else

Answer:

33.33%

Step-by-step explanation:

1. [tex] \frac{5}{12} = \frac{35}{n} \\ 5n = 35 \times 12 \\ 5n = 420 \\ n = \frac{420}{5} \\ n = 84[/tex]

2. [tex] \frac{n}{52} = \frac{180}{120} \\ 120n = 180 \times 52 \\ 120n = 9360 \\ n = \frac{9360}{120} \\ n = 78[/tex]

Answer:

Simplifying

6r + r + -5r = 0

Combine like terms: 6r + r = 7r

7r + -5r = 0

Combine like terms: 7r + -5r = 2r

2r = 0

Solving

2r = 0

Solving for variable 'r'.

Move all terms containing r to the left, all other terms to the right.

Divide each side by '2'.

r = 0

Simplifying

r = 0

7r-5r < this is the answer

6r+r=7r

Answer:

9/2

Step-by-step explanation:

Answer:2.8

Step-by-step explanation: casue yeas.

Answer:

  0.04 = four hundredths

Step-by-step explanation:

To find the value of a digit in a number, set all the other digits to zero.

The value of the 4 is ...

  0.040

The 4 is in the hundredths place, so its value is four hundredths.

Answer:

4 cm

Step-by-step explanation:

Where 7 cm is located is parallel to the side of 11cm

11-7 is 4cm.

Hope that helps!

Answer:

were is the qn?

Step-by-step explanation:

Answer:

Step-by-step explanation:

The third side could have dimension x

32 - 27 < x < 32 + 27

         5 < x < 59

There are a few special triangles

Equilateral triangle could have legs

27, 32, 27

or

32, 27, 32

A right triangle could have the third side

√(27² + 32²) = √1753 which is about 41.87

or

√(32² - 27²) = √295 which is about 17.18

Notice all these fit within the original limits specified.

Answer:

The third side is greater than 5 but less than 59.

Step-by-step explanation:

Remember: Given any two sides of a triangle, the length of the third side is greater than the difference but less than the sum of the length of the two given sides.

So 27 and 32       The given two sides

   32 - 27 = 5        Greater than the difference   (greater than 5)

   32 + 27 = 59     Less than the sum   (less than 59)

Answer:

Step-by-step explanation:

First off, your written problem doesn't match the one you typed. The written problem doesn't have a solution, so I'm going with the typed one (cuz I can solve that one!).

Begin by noting that [tex]e^{-\frac{1}{2}[/tex] is a constant and can be pulled out front of the integration symbol:

[tex]e^{-\frac{1}{2}}\int\limits^\pi _0 {e^{-x}} \, dx[/tex]

Choose u = -x, so du/dx = -1 and -du = dx. Put that - out front along with what's already there to get:

[tex]-e^{-\frac{1}{2}}\int\limits^\pi _0 {e^{-u}} \, du[/tex]

The antiderivative of e^-u is e^-u, so putting it all together and applying the First Fundamental Theorem of Calculus:

[tex]-e^{-\frac{1}{2}}(e^{-\pi }-e^0)[/tex] which simplifies to

[tex]-e^{-\frac{1}{2}}(e^{-\pi }-1)[/tex] which simplifies to

[tex]-e^{-\pi -\frac{1}{2}}+e^{-\frac{1}{2}}[/tex] which has a decimal equivalency of .5803200934

Answer:

b = 1

Step-by-step explanation:

Answer:

I believe that it is function

Answer:

∠ R = 90°

Step-by-step explanation:

The sum of the 3 angles in a triangle = 180° , that is

∠ R + ∠ S + ∠ T = 180° , substitute values

∠ R + 29° + 61° = 180°

∠ R + 90° = 180° ( subtract 90° from both sides )

∠ R = 90°

Answer:

534,070.75 miles

Step-by-step explanation:

The circumference formula is [tex]d\pi[/tex] or [tex]2r\pi[/tex].

But since we're given the diameter, 170,000, all we have to do is multiply it by [tex]\pi[/tex].

[tex]170000*\pi = 534070.75 (Rounded)[/tex]