If you transpose the two digits, the two digits are 10B + A. after reading the above, you can solve the following problem: the sum of two digits of a two digit is 11. If you transpose them, the difference between the new two digits and the original two digits is 45, then you can find the original two digits Let X be the number on the ten digits of the original two digit number, then the one digit number of the original two digit number is X________ The original two digits can be written as_________________ The new two digits can be written as______________ Available equation_____________________

If you transpose the two digits, the two digits are 10B + A. after reading the above, you can solve the following problem: the sum of two digits of a two digit is 11. If you transpose them, the difference between the new two digits and the original two digits is 45, then you can find the original two digits Let X be the number on the ten digits of the original two digit number, then the one digit number of the original two digit number is X________ The original two digits can be written as_________________ The new two digits can be written as______________ Available equation_____________________

Let the number in the original two digit ten be X
Because the sum of the two digits is 11
The original two digit number is 11-x
The original two digits can be written as 10x + (11-x) (or 9x + 11)
The new two digits can be written as 10 (11-x) + X (or 110-9x)
The equation [10 (11-x) + x] - [10x + (11-x)] = 45 can be obtained
Sorted: 18x = 54
The solution is: x = 3
Then 11-x = 8
So the original two digits are: 38
Hope to inspire you!

In the autumn games, Xiaoqiang, Xiaogang and Xiaolin take part in the 100 meter race at the same time. Xiaoqiang is one tenth slower than Xiaogang, and Xiaogang is one tenth slower than Xiaolin
What is the speed ratio of the three of them? (please write down the process)

The ratio of Xie Xiaoqiang and Xiao Gang is: (1-1 / 10): 1 = 9 / 10
The ratio of Xiaogang to Xiaolin is: (1-1 / 10): 1 = 9 / 10 = 10 / 10 * 10 / 9 = 10 / (100 / 9)
So the speed ratio of the three people:
9: 10:100 / 9 = 81:90:100 agree with 1 | comment (1)

Given that the equation | x | = ax + 1 has a negative root but no positive root, the value range of a is ()
A. A ≥ 1b. A ＜ 1C. - 1 ＜ a ＜ 1D. A ＞ - 1 and a ≠ 0

∵ the equation | x | = ax + 1 has a negative root but no positive root, ∵ x ＜ 0, the equation is changed to: - x = ax + 1, X (a + 1) = - 1, x = − 1A + 1 ＜ 0, ∵ a + 1 ＞ 0, ∵ a ＞ - 1, and a ≠ 0. If x ＞ 0, | x | = x, x = ax + 1, x = 11 − a ＞ 0, then 1-A ＞ 0, the solution is a ＜ 1. ∵ a ＜ 1 is not established without positive root, ∵ a ＞ 1. Therefore, select a

Given that there are points a and B on the number axis, the rational numbers they represent are 4 and - 6 respectively
(1) Find the length of line ab;
(2) If point C is the midpoint of line AB, what is the rational number represented by point C?
(3) If D is a point on the number axis, and the rational number represented by D is x, if ad = 3, find the value of X
I don't know if it's right: (1) 4 + - 6 absolute value = 10
（2）10÷2=5
(3) Solution: let the rational number represented by d be X
4x=3
x=3÷4
x=3/4

（1）AB=|4-(-6)|=10
(2) Because point C is the midpoint of line ab
So the rational number represented by C is [4 + (- 6)] / 2 = - 1
(3)AD=|x-4|=3
x-4=±3
The solution is x = 7 or 1

Two gears are meshed with each other. The big gear has 40 teeth, 90 revolutions per minute, and the small gear has 10 teeth. How many revolutions per minute?

Let the pinion rotate x revolutions per minute
40∶10=x∶90
10x=40×90
x=360
Pinion 360 rpm

Equation of first degree with one variable
There are three water pipes a, B and C in a pool, of which a and B are the inlet pipe and C is the drainage pipe. The pool can be filled in 16 minutes by opening a water pipe, 10 minutes by opening b water pipe, and 20 minutes by opening C water pipe. Now open a and B pipes first, and close a and close C pipe after 4 minutes. Q: the pool can be filled in a few minutes
The solution of linear equation with one variable
[design]
[column equation]
[solving equation]

The water tank can be filled in X minutes
The results of the equation are as follows
4/16+X/10-(X-4)/20=1
X/10-X/20=1-1/4-1/5
X/20=11/20
X=11
The pool can be filled in 11 minutes

(1) Find the positive integer solution of the equation x ^ 2-y ^ 2 = 8
(2) If AB satisfies a ^ 2B ^ 2 + A ^ 2 + B ^ 2 + 10ab + 16 = 0, find the value of a ^ 2 + B ^ 2
I'll give you another five points for a good answer
A simple method to calculate: (999 2 / 3) ^ 2 (1000 1 / 3) ^ 2

1. (x + y) (X-Y) = 8, the product of two numbers is 8, find the factor of 8: 1, 2, 4, 8x + y = 8, x + y = 4x-y = 1 (rounding off) X-Y = 2, get x = 3Y = 12, break 10ab into 8ab + 2Ab, then the original formula = (a + b) ^ 2 + (AB + 4) ^ 2 = 0, get a + B = 0 and ab + 4 = 0, so a = 2, B = - 2 or a = - 2, B = 2A ^ 2 + B ^ 2 = 8

It takes about 15 hours for a train to leave Beijing and arrive in Guangzhou. After the train leaves, it will run at the original speed of 8 hours and then arrive in Wuhan. As the world's highest speed railway Wuhan Guangzhou high speed railway officially put into operation in December 2009, the average speed of the train from Wuhan to Guangzhou is more than 50 kilometers per hour, and the time required is also shortened by 4 hours Average speed from Beijing to Wuhan and average speed from Wuhan to Guangzhou after speed up

Let the average speed of the train from Beijing to Wuhan be x km / h, and the average speed from Wuhan to Guangzhou be y km / h after the speed increase. According to the meaning of the question, y = 2x + 5015x = 8x + (15 − 8 − 4) y solves the equations, and x = 150y = 350. A: the average speed of the train from Beijing to Wuhan is 150 km / h, and the average speed from Wuhan to Guangzhou is 350 km / h after the speed increase

Is gravity the same as weight

Gravity is one of the most important and basic concepts in mechanics. However, the definitions of gravity in various textbooks and reference books at home and abroad are not consistent. At present, there are three kinds of definitions of gravity

A batch of cement will be transported 40 tons per day in 4.5 days. If more than 10 tons per day, how many days

Days = 40 × 4.5 ÷ (40 + 10) = 3.6 days