Mathematical problems know that a and B are rational numbers, a > 0, B < 0. Simplify | B | - | a | + | A-B | + | a + B| It is known that a and B are rational numbers, a > 0, B < 0. Simplify | B | - | a | + | A-B | + | a + B|

Mathematical problems know that a and B are rational numbers, a > 0, B < 0. Simplify | B | - | a | + | A-B | + | a + B| It is known that a and B are rational numbers, a > 0, B < 0. Simplify | B | - | a | + | A-B | + | a + B|

When a is near the origin
|b|-|a|+|a-b|+|a+b|
=-b-a+(a-b)-(a+b)
=-b-a+a-b-a-b
=-a-3b
When B is close to the origin
|b|-|a|+|a-b|+|a+b|
=-b-a+(a-b)+(a+b)
=-b-a+a-b+a+b
=a-b

To solve the inequality, we know that two rational numbers a and B satisfy ab | B |, and try to simplify | - 2A | + | - 2b | + ||-|

How is 1 4 9 10 equal to 24

10+9+4+1=24

The dynamic friction coefficient between the object and the horizontal plane is 0.2
Apply a horizontal force of F = 10N to the object, as shown in the figure. After the object moves L = 150m, remove the pulling force F. after a period of time, the object is still, g = 10m / S ^ 2
1. Acceleration during acceleration
2. The maximum speed of the object in motion

F = ma
f=umg
Fhe = fra-f
From the above three formulas, we can get a = 3m / (s ^ 2)
From V ^ 2 = 2As, v = 30 (M / s)

Let Sn be the sum of the first n terms of the arithmetic sequence {an}, if S7 = 35, then A4=______ ．

So the answer is 5

A cyclist starts to ride in a straight line from a standstill. The distances he passes in the first second, the second second, the third and the fourth seconds are 1m, 2m, 3M and 4m respectively
A. The instantaneous velocity at the end of 4S is 2.5m/sb. The instantaneous velocity at the end of 4S is 4m / sc. the average velocity in the first 4S is 2.5m/sd. The average velocity in the fourth s is 4.0m/s

A. according to the first, second, third and fourth seconds, the distance is 1 meter, 2 meters, 3 meters and 4 meters respectively. It is impossible to judge the movement of the bicycle and calculate the instantaneous speed at the end of 4 seconds, so a is wrong and B is wrong. The average speed in C and 4S is. V = XT = 2.5m/s, so C is correct. The average speed in D and 4S is. V = XT = 41m / s, so D is correct

Xiao Ming's mother takes a day off every 4 days, and her father takes a day off every 10 days. They take a day off at the same time on March 1. How early can they take a day off at the same time?
Take a calendar and figure it out

Xiao Ming's mother takes 5 days off for every 4 days of work, and his father takes 11 days off for every 10 days of work. Then their time off at the same time is the least common multiple of 5 and 11

The purchase price of a commodity is x yuan per piece and the retail price is 900 yuan per piece. In order to adapt to the market competition, if the store sells at 10% discount of the retail price and gives a profit of 40 yuan, it can still make a profit of 10%, then x is ()
A. 700B. About 773c. About 736d. About 856

The purchase price is x, and the countable equation x × (1 + 10%) = 900 × 90% - 40. The solution is x = 700 yuan, so a

Given that a is a root of the equation x & # 178; - 3 + 1 = 0, find the value of 2A & # 178; - 6a-2 + 3A / A & # 178; + 1

∵ A is a root of the equation x & # 178; - 3x + 1 = 0
If a & # 178; - 3A + 1 = 0, then a & # 178; - 3A = - 1, a & # 178; + 1 = 3A
2a²-6a-2+3a／a²+1
=2（a²-3a）-2+3a/（a²+1）
=2×（-1）-2+1
=-2-2+1
=-3

There is a six digit number. The three digits on the left are the same, and the three digits on the right are three consecutive natural numbers. The sum of the six digits is equal to the two digits at the end. What is the six digit number?

Let six digits be aaabcd, where B, C and D are continuous natural numbers, then a + A + A + B + C + D = 3A + 3C = CD = 10C + D. because B, C and D are continuous natural numbers, B = C-1, or D = C + 1