The equation [X-2 / 1 (x + 1)] + 1 = 0, has an increasing root, followed by an increasing root

The equation [X-2 / 1 (x + 1)] + 1 = 0, has an increasing root, followed by an increasing root

A:
[X-2 / 1 (x + 1)] + 1 = 0
2 (x + 1) / (x ^ 2-1) + 1 = 0 has increasing roots, x ^ 2-1 ≠ 0, X ≠ - 1 and X ≠ 1
2(x+1)/(x^2-1)=-1
2x+2=1-x^2
x^2+2x+1=0
x=-1
The increasing root is x = - 1

Find the equation of the circle with (X-2) square + (Y-1) square = 4 symmetric to the line X-Y + 2 = 0
How to find the symmetry point of the center of a circle

Let the symmetric point be X'Y '
(x'+2)/2-(y'+1)/2+2=0
(y'-1)/(x'-2)=-1
The solution is x '= - 1, y' = 4
There is also a simple algorithm
From X-Y + 2 = 0
X = Y-2, y = 1, the solution is x = - 1
Y = x + 2, x = 2, the solution is y = 4

The equation of a line passing through a point (- 1,2) and parallel to the x-axis, the equation of a line parallel to the y-axis, and the equation of a line passing through the origin

The straight line passes through the point (- 1,2),
And the linear equation parallel to X axis is y = 2
And the linear equation parallel to the Y axis is x = - 1
And the linear equation passing through the origin is y = - 2x

The length of train a and train B are 144m and 180m, and train a runs 4m more per second than train B. the two trains are facing each other, and it takes 9s from meeting to staggering. What's the speed of the two trains?

Suppose car B travels XM per second, then car a Travels (x + 4) m per second. According to the meaning of the question, we get: 9 (x + X + 4) = 144 + 180, sort out: 2x = 32, solve: x = 16, then car a travels 20m per second, car B travels 16m per second

The average of the five numbers is 40. Arrange the five numbers from small to large, the average of the first three numbers is 35, the average of the last three numbers is 45, and what is the number in the middle
Why 40

35×3+45×3-40×5=40
The average of the first three numbers is 35, so the sum of the first three numbers is 35 × 3
The average of the last three numbers is 45, so the sum of the last four numbers is 45 × 3
The first three and the last three, a total of 3 + 3 = 6 numbers
But five numbers are known
What's the extra number?
Arrange the five numbers from small to large
The first three include the middle number
The last three also include the middle number
Add up the first three and the last three, and the number in the middle will be added again
Subtract the sum of five numbers, and the rest is the middle number
I don't know if you can understand it

A and B vehicles run from AB and ab at the same time. When they start, the speed ratio of a and B vehicles is 3:2. After the two vehicles meet, a vehicle speeds up by 20% and B vehicle speeds up by 30%
When car a arrives at B, car B is 56 kilometers away from A. how many kilometers are there between a and B?

The original speed of B is 2 / 3 of that of A. now the speed of B is 1 + 30 + 130% of that of A. now the speed of B is 1 + 20 + 120% of that of A. now the speed of B is 2 / 3 × 130% = 13 / 15. Then the speed ratio of a to B is 120%: 13 / 15 = 18:13

It is proved that the sum of interior angles of convex n-polygon (n ≥ 3) is equal to (n-2) π (PAI)

The polygon is divided into n-2 triangles by diagonals from a point to other points except its left and right points. Since the sum of internal angles of each triangle is 180 ° or π, the sum of internal angles of n-2 triangles is equal to (n-2) π

On a map with a scale of 1:6000000, the distance between a and B is 15 km. If a car runs at a speed of 75 km / h at 9 am, the distance between a and B is 15 km
How long does it take to get to place B from place a?

Actual Julu = 15 × 6000000 △ 100 △ 1000 = 900 km;
Time = 900 △ 75 = 12 hours;
So we arrived at 9 p.m
If you don't understand this question, you can ask,

Given the function f (x) = root 2cos (2x + π / 4), find the maximum and minimum value of F (x) in the interval [- π / 8, π / 2], and find the value of X at the maximum value

x∈【-π/8,π/2】
2x+π/4∈【0,5π/4】
Therefore, when 2x + π / 4 = 0, there is a maximum y = √ 2, x = - π / 8
When 2x + π / 4 = π, there is a minimum value y = - √ 2, x = 3 π / 8
Range [- √ 2, √ 2]

A batch of coal is transported to the canteen. It is planned to use 1 / 5 of the coal every day. What percentage of the coal will be used in 4 days?

A batch of coal is delivered to the canteen. It is planned to use 1 / 5 of the coal every day and 4 / 5 of the coal in 4 days