Bivariate linear equation, 4x-3y = 12, what is y when x is 1.2.3

y=x*4/3-4
When x = 1, y = - 8 / 3
When x = 2, y = - 4 / 3
When x = 3, y = 0

1+12+123+1234+12345
simple and convenient

The limit problem of higher number on logarithm e
Let f (x) = 1 / (1 + e ^ (1 / x)), then limf (x) =? Limf (x) =?
x→0+ x→0-
Due to my poor logarithm, please explain the reason or apply the formula

In this way, when x → 0 +, the value of 1 / X tends to infinity, so e ^ (1 / x) also tends to + ∞, so 1 / (1 + e ^ (1 / x)) in X → 0 +, limf (x) = 02. Similarly, when x → 0 -, the value of 1 / X tends to negative infinity, so e ^ (1 / x) also tends to - ∞, so 1 / (1 + e ^ (1 / x)) in X → 0 +, limf (x)

What is the result of "200" - "100"?

The minus sign in VFP is also a character connection
Function to remove the leading space of the next character
as
"123 spaces" - "spaces 456"
="123 spaces 456"
"123 spaces" + "456 spaces"
="123 spaces 456"

Where is the Three Gorges located?

Located in the middle and upper reaches of the Yangtze River, the Three Gorges is a grand canyon with magnificent scenery
It starts from Baidi city in Fengjie County of Chongqing in the West and ends at nanjinguan in Yichang city of Hubei Province in the East. It is composed of Qutang gorge, Wuxia gorge and Xiling Gorge, with a total length of 193 km

Why can higher order infinitesimal be omitted?
In the definition of integral, the sum is only the approximate value of area, and then it becomes the exact value after finding the limit. It is said in the book that the whole area is divided into several small curved trapezoid areas, and each small curved trapezoid is approximately replaced by a rectangle. They are only one higher order infinitesimal difference of DX. But after finding the sum, there are infinitely many higher order infinitesimals, How many infinitesimals of higher order add up and take the limit is not necessarily equal to zero?

The landlord is my confidant! I just proved this problem a few days ago. I'll come back to see the answer in the evening!
First of all, please draw the xoy coordinates on the draft paper, and then draw a closed area surrounded by a curve on it. We call it area D
Suppose that the area of this closed area is s (d) and the side length is l (d)
Now we are going to prove theorem 1:
If the coordinate system is divided by equidistant parallel lines parallel to the x-axis and y-axis, then when the division is infinitely fine, the limit of the area of the small square falling inside D is the area of the region D. (imagine the following with your head, in fact, this is also the reason why we can use DXDY approximation to express the integral region in solving double integrals.)
Lou Zhu's theorem can be regarded as a special case of Theorem 1. Before proving theorem 1, we first prove that theorem 1 can deduce Lou Zhu's theorem
The theorem of proof
Theorem 0: (landlord's theorem)
Let a continuous function be defined in the domain [x0, X1]. We call the closed region bounded by the curves y = f (x), x = x0, x = x1, and X-axis D, and let its area s (d). We divide the region by equidistant parallel lines parallel to y-axis. The sum of all small rectangles is denoted as ∑ Si. When the distance between parallel lines is infinite, there must be Lim ∑ Si = s (d)
If we have got theorem 1, then we can divide the square like this: after the small rectangle in theorem 0 is divided, I will divide it according to the width of the division
We keep these parallel lines and make an equidistant partition parallel to x, so that the side length of the small square is equal to the width of the small rectangle, and any small square is equal
Obviously, the area of the small rectangle and ∑ Si > = the area of the square and ∑ SZ, that is ∑ SZA
.+ln >a
l(n-1)+l(n)+l1+l2 >a
ln+l1+l2+l3 >a
Notice that each Li appears four times
Add all the left and right sides to get:
4L(D)>n*a (1)
For a fixed closed region, its side length l can be regarded as a constant, so it has some properties
N < K / a (k is a constant, a is the side length of a square) (2)
Suppose that for the first partition, the number of boundary squares is N1, the number of internal squares is M1, and the length of square side is A1
The second division principle is: the side length becomes 1.5 of the original, so a square becomes 4 squares, so
M2 > = 4m1 (because the original ones on the boundary may be delimited, the number of M will only increase)
n2

What's two ninths plus five eighties plus seven nines?

13 / 8

1129,1228,1327.2020
If the two factors of the opportunity are represented by letters A and B respectively, please observe and write the relationship between AB and a + B

a=10+n
b=30-n
ab = (10+n)(30-n) = (n-10)(n-30) = 300 + 20n -n^2
a+b = (10+n)+(30-n) = 40

If there are 2K + 1 terms in the arithmetic sequence {an}, and the sum of all odd terms is 132, and the sum of even terms is 120, then K= ,aK+1= ,

There are K + 1 odd and K even terms in 2K + 1 term
Sum of odd terms = [A1 + a (2k + 1)] * (K + 1) / 2 = 132 (1)
Sum of even terms = [A2 + a (2k)] * k / 2 = 120 (2)
∵ a1+a(2k+1)=a2+a(2k)
(1)/(2)
(k+1)/k=132/120=11/10
∴ k=10
∴ [a2+a(2k)]*k/2 =120
∵ a2+a(2k)=a(k+1)+a(k+1)
2a(k+1)*10/2=120
∴ a(k+1)=12

There are 20 pieces of RMB 2 yuan, 5 yuan and 10 yuan, with a total of 122 yuan. Among them, there are as many pieces of RMB 2 yuan and 5 yuan, and how many pieces of RMB 10 yuan
emergency
No equations

10 * 20 = 200 yuan
200-122 = 78 yuan
5-2 = 3 yuan
78 / 3 = 26 yuan
26-2 * 5 * 2 = 6 sheets
20-6 * 2 = 8 sheets
Answer: there are 6 tickets for 2 yuan, 5 yuan and 8 tickets for 10 yuan

Bivariate linear equation, 4x-3y = 12, what is y when x is 1.2.3