Help with math problems, elementary school, thank you!

The core of the chase problem is: speed difference, time difference, distance difference. In this example, it is clear that A is faster than B.

From the fact that A asks B to run 10 meters first, then A can catch up with B by running for 5 seconds: 5 (A B) 10 meters, then: A B 10 5 = 2 meters and seconds.

B runs 2 seconds ahead of A, and A can catch up with B by running 4 seconds: The distance that A can catch up with in 4 seconds: 4 (A B) 4 2 8 meters, these 8 meters is the distance of B running 2 meters first, then B's speed: 8 2 = 4 meters in seconds.

A speed: 2 4 6 m sec.

Let A's velocity be x, because A lets B run 10 meters first, then A can catch up with B by running for 5 seconds, so B's velocity is (5x-10) 5=(Simplify) x-2

Explanation: 5x is for A to run 10 meters later, so from the time A starts running, B runs 5x-10 distance, and it takes 5 seconds for A.

And because if B runs 2 seconds ahead of A, A can catch up with B by running 4 seconds. So the equation can be listed: (x-2)(2+4) 4x

Explanation: B runs 2 seconds ahead of A, so A's 4 seconds of running is equal to B's 4 seconds of running A's run plus his 2 seconds of running.

Finally, the equation is solved.

A asks B to run 10 meters first, then A can catch up with B by running for 5 seconds, indicating that A is faster than B per second: 10 5 = 2 meters per second.

If B runs 2 seconds ahead of A, A can catch up with B by running 4 seconds.

A runs more in 4 seconds than B: 2*4=8 meters.

Illustrates that B ran 8 meters more than A in 2 seconds before A.

So B's velocity is: 8 2 = 4 m s.

Then the velocity of A is: 4 + 2 = 6 m seconds.

From: B runs 10 meters first, then A can catch up by running for 5 seconds.

It can be seen that the speed difference between the two is: 10 5 2 (meters).

Because: B runs 2 seconds ahead of A, then A can catch up with B by running 4 seconds.

Then A runs more than B: 4*2 8 (m).

Then B runs per second: 8 2 4 (m).

Then A runs per second: 4 + 2 6 (m).

Solve the equation. Let A be x and B be y

For the first time, because the distance between the two runs is equal.

5x=5y+10

The second time is due to the equal distance and time relationship between the two.

2y+4y=4x

The solution is x=6 y=4

A asks B to run 10 meters first, then A can catch up with B by running for 5 seconds.

then A runs 2 meters more than B per second;

B runs 2 seconds ahead of A, then A can catch up with B by running 4 seconds.

Then A runs 8 meters more than B in 4 seconds (the one who runs more is the one who runs first), so B runs 4 meters per second (8 2).

A runs 6 meters per second (4+2).

10 5 = 2 (m) ......A is 2 meters faster than B per second.

2 4 = 8 (m) ......The number of meters that A runs more than B in 4 seconds, that is, the distance A has to chase, is exactly what B ran 2 seconds first.

8 2 = 4 (m) ......B runs 4 meters per second.

4+2=6 (m) ......A runs 6 meters per second. A is 2 meters faster than B per second.

Let A run x meters per second and B run y meters per second.

5x=5y+10

4x=(2+4)y

Solve systems of equations. x=6,y=4

Let the velocity of A be x and the velocity of B y

then there is; 5x=5y+10

4x=6y: x=6, y=4

Let A x m second, B y m second.

5x=5y+10

4x=2y+4y

The solution is x=6 msec, y=4msec.

If A asks B to run 10 meters first, then A can catch up with B by running for 5 seconds, let B x A x+2 6x=4x+8 x=4 A 6m s B 4m s

You can set the speed of the armor to xm s first. The velocity of B is ym s, and then two equations 5(x-y)=10 and 4(x-y)=2y, which can be found by using a binary one-time equation, x=6 and y=4

The distance they run is self-equal, from condition 1 to get 5v A = 5v B + 10, from condition 2 to get 4v A = 2v B + 4v B = 6v B, so v A = 4 m seconds, v B = 6 m seconds.

Solution: The total amount of work is 1, then A's work efficiency is three-thirds, and B's efficiency is two-thirds.

The formula can be calculated from the meaning of the question: (1-25%) divided by (one-third + one-half), (one-third + one-half) is the total amount of work they do in an hour, subtract the work done by A by unit, and the rest is the work of two people, so that the working time = total work divided by work efficiency and.

Question 4: One-eighth.

Question 5: Stare at the plexus 40 + 15-18 = 37

The first congratulatory six kai cherry blossom question: (40-12 2) 2=8