Primary school math problems please write the solution process .

1. Find the law:

6 1=10 (6-1=5,5*2=10 ), 8 2=12 (8-2=6, 6*2=12), 5 2=6 (5-2=3, 3*2=6), so 9 8=( ) is inferred to (9-8=1, 1*2=2). 9 8 = ( ) parentheses are (2).

2 2 = 7 (2 * 2 = 4, 4 + 3 = 7), 5 7 = 38 (5 * 7 = 35, 5 + 3 = 38), 6 5 = 33 (6 * 5 = 30, 30 + 3 = 33), so 4 4 = ( ) is inferred to be (4 * 4 = 16, , 1 + 3 = 19). 4 4 = ( ) parentheses are (19).

2. Cut a piece of wood into two sections, the first section is 3 5 long, and the second section accounts for 3 5 of the whole field, then the result of the comparison of the length of these two sections of wood is ( ) a the first section is longer than the second section b the second section is longer than the first section c can not be determined d the two sections are equal.

First, let's look at the third sentence of the title. The second paragraph accounts for 3 5 of the whole field, which means that the first paragraph can only have 2 5 of the whole field (1-3 5 = 2 5), and the answer is a

3. A pair of shoes, if sold for 140 yuan, you can earn 40%, and if you sell for 120 yuan, you can earn ( ).

The original value of the shoes was $100 (140 (1+40%)=100). If you sell for $120, (120-100) 100 = 20%.

Yes (front number - back number) 2, so 9 8 = (2 )

is the number before and after + 3, so 4 4 = ( 19).

2. Cut a piece of wood into two sections, the first section is 3 5 long, and the second section accounts for 3 5 of the whole field, then the result of the comparison of the length of these two sections of wood is (b).

a. The first paragraph is longer than the second paragraph, b. The second paragraph is longer than the first paragraph, c. It is not possible to determine that the two paragraphs are equal.

Because the second paragraph is three-fifths of the total length, the first paragraph is 1-three-fifths of the total length = two-fifths so the second paragraph is longer than the first paragraph.

3. A pair of shoes, if sold for 140 yuan, you can earn 40%, if you sell 120 yuan, you can earn (20)%.

Buy 140 yuan can earn 40%, indicating that the original price of (1+40%)=140, so the original price of shoes is 140 (1+40%)=100

So sell for 120 yuan to earn (120-100) 100=20%hope!

2. The second paragraph is long, choose B, because the first paragraph accounts for 2 5

3. Assuming that the cost of shoes is x yuan, then (140-x) x=40%, x=100,120-100) 100=20%.

1.(1) The answer is 2 6-1 = 5 5 and then x2 = 10 (2) Answer 19 Multiply the two numbers and add 3

2. Let the full length be x the first paragraph 3 5 The second paragraph 3 5 x x must be greater than 3 5 3 5 + 3 5x=x The solution of x= So choose b

Then 120---=divided by 140 is approximately.

1.(1) The first number is multiplied by the second number by 2, so it is 9-8 = 1 1 * 2 = 22) The first number is multiplied by the second number plus 3, so it is 4 * 4 = 16, 16 + 3 = 192b, the second paragraph accounts for 3 5 of the total length, and the first paragraph accounts for 2 53

The original price of shoes is 140 (1+40%)=100, (120-100) 100=20%.

1、（1）（6-1）x2=10，（8-2）x2=12.。。9-8）x2=2

2）2x2+3=7,5x7+3=38.。。4x4+3=192, b The length of the first section is 3 5 meters, accounting for 1-3 5=2 3, the original price = 140 (1 + 40%) = 100 yuan.

The second section accounts for 3 5 of the total length, then the first section stands for 2 5 of the total length, so the second section is longer than the first section.

Reverse Extrapolation:

First to last: 8 pieces.

The penultimate step: (8-1) x2 = 14 blocks.

The third to last step: (14+5)x2=38 blocks.

The penultimate step (the beginning): 38x2=76 blocks.

She Xiaohua originally had x pieces of candy.

Gave Xiao Ming (1 2) x pieces of sugar