Elementary School Math Problem Solving, Primary School Math Problem

A: The two meeting points are 60 kilometers apart.

Solution: Let the velocities of A and B be x, y, and the distance between ab and s respectively. The time of departure from AB is 0, the first meeting time is T1, and the second meeting time is T2.

then at the first encounter (x+y) t1=s

and y t1=60

In the second encounter, x*(t2-t1)=s+60-40=s+20y*(t2-t1)=s+40-60=s-20 are added to the equation: (x+y) (t2-t1)=2 s and (x+y) t1=s

Therefore, t2-t1=2 t1

then, y (t2-t1) = y 2 t1 = 2 (y t1) = 2 60 = s-20

s=140

The distance between the two meeting points is: 140-60-40=40

60*3-40=140 km.

Once you draw the line segment diagram, the quantity relationship becomes obvious. Each line of a car departing from B traveled 60 kilometers, they traveled a total of three journeys, and the car departing from B traveled a total of three 60 kilometers, that is, 40 kilometers more than the whole journey, so the whole journey is 60*3-40=140 kilometers.

60*3-40=140(km)

The two meeting points are 140 kilometers apart.

The number of heads + the number of heads is equal to 2 times the number of heads.

The number of heads is equal to 0

Count only the number of heads, which is equal to the square of the number of heads.

Count only the number of heads, which is equal to 1

99 is equal to: number of heads (number of heads + 2).

So the number of heads is 9

The sheep has only one head, so the number of heads is equal to the number of heads.

Head + only = 2 times the head.

Head-only = 0 head * only = head * head.

The head divides only = 1, so it adds up to the head * head + 2 * head + 1 = 100

If the head = 10, then the result is greater than 100, so the number of heads must be less than 10, starting from 9 and counting backwards, it is found that 9*9+2*9+1 is exactly equal to 100, so there are 9 heads, that is, there are nine sheep.

Set the number of heads to y.

A sheep has only one head.

The number of sheep is equal to the number of heads.

y+y)+(y-y)+(y's squared) + (y divided by y)=100 gives y=9

That is: there are 9 sheep.

One sheep with one head.

The number of heads plus the number of heads) + (the number of heads minus the number of heads) + (the number of heads multiplied by the number of heads) + (the number of heads divided by the number of heads) = the number of heads + the number of heads + the number of heads + the number of heads = 2 * the number of heads + the number of heads + the number of heads + 1

Number + 1) * (number + 1) = 100

Count +1 = 10

Number = 10-1 = 9

Head plus only = head 2

Head reduction only = head 0

Multiply only the head = the square of the head.

Add head only = head 1

99 is equal to: number of heads (number of heads + 2).

So the number of heads is 9

That is, there are 9 sheep.

Method 1: No xDon't use equations, use simple equations.

Number of heads + number of heads + number of heads + number of heads number of heads + number of heads Number of heads + number of heads Number of heads = 100 The number of sheep is equal to the number of heads.

The equation becomes: number + number + 1 = 100 number + number + number number = 99

The square of the number is less than 100, that is, the number is between 1 and 9.

It can be seen that the number of sheep is 9

Method 2: Equations.

Number of heads + number of heads + number of heads - number of heads + number of heads number of heads + number of heads number of heads = 100 Let the number of sheep be x, that is, the number of heads of sheep is also x

x+x+x-x+x2+1=100

x2+2x+1=100

x+1)2=102

x+1=10

x = 9 sheep with nine.

Solution: If the number of heads is a, then the number of heads is also a

a+a)+(a-a)+a²+a÷a=1002a+0+a²+1=100

2a+a²=99

a(a+2)=99

Because a is an integer.

So a=9

You've been too experienced, aren't you? Genius!

1. Solution: According to the analysis of "A accelerates and walks 2 kilometers per hour, B sets off an hour in advance, and meets at Shengli Bridge again", the second time it took 3 hours to meet at Shengli Bridge, and walked 2 kilometers more per hour, and a total of 1 kilometers more kilometers per hour, that is, A needs to use an hour of attitude source for 5 kilometers and 5 kilometers an hour, and finds the original speed of A of 10 kilometers and hours.

A similar analysis is used to find the original velocity of the trace state B: 3 7 km h.

The two towns in the north and south are (10 14) * 3 72 kilometers apart.

A: The north and south towns are 72 kilometers apart.

Let the distance be s, then s is equal to ten minus s fifteen is equal to two, then s is sixty kilometers, when he rides ten kilometers per hour, then he rides sixty to ten equals six hours, and when he arrives at one o'clock in the afternoon, the departure time is seven o'clock in the morning! Now if he wants to arrive at twelve o'clock, he will have to ride for five hours, sixty to five equals twelve, and the speed is twelve kilometers per hour.

The small army should ride x kilometers per hour.

The difference between 1 p.m. and 11 a.m. is 2 hours.

If you arrive at 12 noon.

Difference of 1 hour.

2 hours is twice as much as 1 hour.

So 1 10-1 15 = 2 (1 x - 1 15) 2 x = 1 10 + 1 15 = 25 150

x=12

A + B = 42 * 2 = 84 A + C = 46 * 2 = 92 B + C = 47 * 2 = 94

Then 2A + 2 B + 2 C = 2 (A + B + C) = 84 + 92 + 94 = 270 So A + B + C = 270 2 = 135

So C = 135-84 = 51 B = 94-51 = 43 A = 84-43 = 41

Hopefully, hehe.

42 2 + 46 2 + 47 2 = A B + A C + B C = 2 A + 2 B + 2 C = 270, 270 2 = 135, that is, the sum of the three numbers of A, B B and C. The number of A is.

135－94＝41。The number B is 135 92 43. The number C is 135 84 51, whether you want to find the three numbers of A, B, C or not This is the simplest direct method!!

The sum of A and B is.

The sum of A-C is.

The sum of Ethyl and C is.

The sum of A, B, C, is.

The number of A is. The number B is. C number is.