Two elementary school 4th grade math problems, two primary 4 math problems

From: The elder brother was not convinced, and the younger brother had to give the elder brother 5 yuan, and the elder brother picked 2 more yuan than the younger brother.

I learned: At this time, brother = 12, brother = 14.

After my brother snatched half of it from my brother, my brother had 18 yuan.

Let's say that the younger brother has x blocks, and the younger brother has y blocks.

The system of equations is obtained: (1) x+y=26

2）y+x/2=18

Solve the equation to obtain: x=16, y=10

Let the pieces have x pieces, and after the first score, each piece is (x-1) 4 pieces.

After the second division, it is actually to divide (x-1) 4 into 4 equal parts again.

Each serving is (x-5) 16 pieces.

By: The rest is divided into 4 equal parts and there is one left. Q: How many pieces were there at least?

(x-5) 16=5

Solve the equation to obtain: x=85

It's okay, but there's no paper, and I'll help you make it if you have paper.

1) Younger brother 16 Elder brother 10

Using the backward method, at the end.

Younger brother 12, elder brother 14

The previous brother is 17 and the elder brother is 9

One step further up brother 8, brother 18

One step further brother 16, brother 10

The same is done with the backward method.

The last 4 equal parts are left with 1 piece, and the minimum is 5

That last time it was 21, 4 equal parts were 5 per portion, and 1 remained

The last time it was 85, 4 aliquots were 21 per portion, and 1 remained

The fourth grade questions are too difficult...

(1) Distance s=42t+45t=87t

2) From the above, it can be obtained: when t=3, s=87t=87*3=261 (km).

(1) The distance between two places s= (42+45)*t = 87t

2) When t=3, the distance between the two places is s= 87*3 = 261 (km).

Profit and loss issues.

Profit + loss) difference between two distributions = number of units.

20+16) (16-10)=6 (pcs).

16*6-16=80 (book).

Set x classes, then 16x-16=10x+20, get x=6; 6*10+20=80。A total of 80 books in 6 classes.

Design: There are x classes in total.

16x-16=10x+20

Solve x = 6 to buy back 10 * 6 + 20 = 80 copies.

Solution: There are x classes.

16（x-1）=16x+20

x=6(6-1)*16=80

A: There are 80 books in 6 classes.

After the rope is folded in half, it is measured, and the rope is different meters.

So the rope is shorter than 2 times the wood.

and the rope was a meter longer than the wood.

So, the wood is long meters.

The rope is long in meters, the wood is in length, and the rope is 3 meters long.

(The rope is 3 meters long and the wood is 3 meters long.)

Let the rope be x and the wood be y

x-y=y-(1/2)x=

The solution is x=3, y=

Let the rope be x long and the wood y long

x-y=x/2+

The solution is x=3, y=

Solution: If the length of the wooden block is x meters, then the length of the rope is (x + meters.

According to the title, it gets:

x+——= x

2 solution: x = m).

Then: the length of the rope is: x+ + m).

A: ......

Rope length (m).

Wood is 3 meters long) Answer: The rope is 3 meters long, and the wood is 1 meter long.

Set the rope x meters.

1 2x=x=3 m Wood = m.