Please help me with a math problem

The motorcycle went 24 kilometers first.

There are 240-60 = 180 kilometers left.

It takes 180 (24+36) = 3 hours for the two cars to meet.

So 3+ hours.

Motorbikes can be met by cars in the hour after they leave.

Subtract the distance traveled by the motorcycle first: km).

Set: Meet after x hours.

This gives 24* +24x + 36x = 240, and we get : x = 3

This is the answer x + = the answer.

Set to x hours, 240 first subtract by 24 to get x plus 24 times x equals 180 to get x = 3

First of all, the distance to go alone by motorcycle: 24*km.

Then find the distance traveled by the car and the motorcycle: 240-60 = 180 km.

Set x hours later to meet the car.

36x+24x+24*

60x=240-60

x=180/60

x = 3 (hours).

The side length of the chosen tablecloth should not be less than 1 meter, that is, 100 cm.

In Grandpa Wang's selection, the side length of the tablecloth is: 3140 square centimeters Congsun), 1000 100 10, which is not suitable for the permeable ear chain.

The third type has one side that is shorter than 100 cm, which is also not suitable.

The first type of side is more than 100 cm, so it is more appropriate to choose this one.

Solution: Set the number of questions that were not done to x questions.

Two-thirds x + x = (x-30) 3/3 10 five-thirds x = (10x-300) 3/3

5x =10x-300

5x =-300

x = 6060 + 60 two-thirds = 100 (channel).

A: There are a total of 100 oral arithmetic questions.

Column solution: 30 (7/10 - 2/5) = 100 Note: 7/10 is 7 (7+3)=7 10 The number of questions that have been done after 30 more questions.

Two-fifths is 2 (2+3)=2 5 The number of questions that have been done is the number of shares.

Set the undone oral arithmetic problem has x channels, 3 (2 3x+30) = 7 (x-30) process to solve by yourself, it is difficult to play here, solve x = 60, the number of problems that have been done: 60 2 3 = 40 (Dao), the total number of questions: 60 + 40 = 100 (Dao) is different, the problem solving process may be different, you refer to it!

First of all, it's none of my business to be wrong).

There are a total of 100 questions, the first time is 40 but not 60, and the second time is 70 but not 30

Set x questions but not y questions.

According to the question, x=(3 2)y

3（x+30）=7y

Solve a system of equations to get the answer.

2s/（s/v1+s/v2）

2÷（1/v1+1/v2）

2÷[(v1+v2)/v1v2]

2v1v2（v1+v2）

The distance between port A and port B is s, if the speed of a ship from port A to port B is v1, and the speed of returning from port B to port A is v2, then the average round-trip speed of the ship is 2v1v2 (v1+v2).

2s/(s/v1)+(s/v2)

This is the total distance traveled twice, divided by the sum of the two times.

Time from port A to port B = s v1

The time from port B to port A = s v2

The average round-trip speed of the ship = 2s (s v1 + s v2).

Multiply all three formulas by 60 at the same time.

15 (3 x + 2 y) = 12 (2 x + y) = 10 (x-y + 1) and then divide into any two equations.

15(3x+2y)=12(2x+y) (1)12(2x+y)=10(x-y+1) (2) simplification yields 7x+6y=0 (1).

7x+12y-6=0 (2)

From Eq. (1) we get 7x=-6y (3).

Substituting Eq. (3) into Eq. (2) gives 6y=6, so substituting y=1 into Eq. (3) gives x=-6 7

So the solution of the equation is x=-6 7, y=1

Also divide by 60Get.

45x+30y=24x+12y=10x-10y+10.

Split into two any two equations.

45x+30y=24x+12y

24x+12y=10x-10y+10

Y = is available