A and B go to the library to borrow books. A goes every 4 days, B goes every 6 days. If they meet in the library on January 10, what's the next meeting?

A and B go to the library to borrow books. A goes every four days and B goes every six days. If they meet in the library on January 10, the next time they meet is on January 22

A and B go to the library to borrow books. A goes to the library every four days and B goes to the library every five days. If they meet in the library on July 1, what month and day will they go to the library at the same time?

4 = 2 × 2, so the least common multiple of 4 and 5 is: 2 × 2 × 5 = 20; that is to say, they will both arrive at the library in 20 days, 1 + 20 = 21. A: then the next time they arrive at the library at the same time is July 21

Xiaomin and Xiaofang go to the library to read books. Xiaomin goes to the library every two days. Xiaofang goes to the library every three days. They meet in the library on August 1. The next time they meet

The least common multiple of 2 and 3 is 6
1＋6＝7
The next time we meet on August 7th

The inequality (m-2) x & sup2; + 2 (m-2) x-4 > 0 holds for all real numbers x, and the value range of real number m is obtained
I want to know if there is a problem with this problem (absolutely correct). When x is 0, it's an empty set. But the problem says that all real numbers x are true. Isn't it contradictory?

If the title is no problem: 1) when m-2 = 0, that is, M = 2, the inequality can be changed to - 4 > 0, which can not be tenable, and 〈 m ≠ 2; 2) when m ≠ 2, to make the inequality tenable for any x, it needs m-2 > 0 and △ = 4 (m-2) & sup2; + 16 (m-2) 2 and - 20, which is obviously tenable, and 〈 M = 2 is in line with the title; 2) when m ≠ 2, to make the inequality tenable for any X

The distance between a and B is 270 km. The passenger cars and freight cars run from the two places for 3 hours at the same time. The ratio of passenger cars and freight cars is 5:4. The speed of passenger cars and freight cars is calculated

The speed sum of passenger cars and freight cars is 270 △ 3 = 90 km / h
5+4＝9
The speed of the bus is 90 × 5 / 9 = 50 km / h
The speed of truck is 90 × 4 / 9 = 40 km / h

Please fill in some concept blanks of high school mathematics for me
1. The domain of a function is to make the function________ Set of
2. Three common types of questions determine the domain of definition
(1) If you know the analytic expression of a function, that is_
(2) In accordance with the definition field of function f [g (x)], it is necessary to guarantee the inner function g (x) d The field is the property of outer function f (x) field
(3) The domain of practical application problem is to make_____ The value set of meaningful independent variables

1, make the function hold, all the nonempty number sets of X constitute
2. 1) the value range of X that makes the analytic expression meaningful
2) Range definition field
3) Meet the conditions of practical problems

Party A and Party B have two engineering teams. Party A has 120 people, and 20% of team a is transferred to team B. at this time, two-thirds of team B is just the number of team a

Set the number of team B as X, 120-120 * 20 / 100 = 2 / 3x
X = 64
That is team B for 64 people

Given A-B = 40, B-C = - 50, a + C = 20, find the square of a minus the square of C

a-b=40,b-c=-50
Add left and right separately
a-b+b-c=40+(-50)
a-c=-10
a+c=20
a^2-c^2=(a+b)(a-c)=-10*20=-200

Car a and car B drive from a and B at the same time. Car a travels 60 kilometers per hour. Car B runs 45 times faster than car A. after 56 hours, the two cars meet. How many kilometers are there between a and B?

(60 × 45 + 60) × 56 = 108 × 56 = 90 (km) answer: A and B are 90 km apart

As shown in the figure, in △ ABC, ad and be are two midlines, then s △ EDC: s △ ABC=______ ．

∵ in △ ABC, ad and be are two middle lines, ∵ de ‖. 12ab, ∵ s △ CEDs △ ABC = 14, so the answer is: 1:4

A and B go to the library to borrow books. A goes every 4 days, B goes every 6 days. If they meet in the library on January 10, what's the next meeting?