It s gone, but I m in a hurry, and I m asking a well wisher to solve a math problem in the first yea

The product of two numbers that are reciprocal to each other is 1, that is, a*2b = 1, and the sum of two numbers that are opposite to each other is 0, that is, -c+d 2=0, -2c+d=0, and x=plus or minus 3, then the algebraic formula = 1 + 3 3 = 2 or 1-3 3 = 0

Solution: According to the meaning of the question, it can be known that a 2b = 1 that is, 2ab = 1c + d 2 = 0 that is, -2c + d = 0

x=3 or x=-3

So 2ab-2c+d+x 3=1+0+1=2 or 2ab-2c+d+x 3=1+0-1=0

Solution: Derived from the question.

a×2b=1 -c+d/2=0 |x|=-3 or +31When x=+3, 2ab-2c+d+x 3=1+3=42When x=-3, 2ab-2c+d+x 3=1+(-3)=-2

A and 2b are the reciprocal of each other, 2ba=1

c and d 2 are the opposite of each other -c+d 2=0|x|=3 ∴x=±3

2ab-2c+d+x 3=1+2(-c+d2) 1=1+0 1=0 or 2

Knife holder x blade is sold and 50x

A: Profit of each razor Total profit = 8400 * yuan B: Profit is twice that of A = 4200 * 2 = 8400 yuan The knife holder loses 4 yuan per knife holder, and the blade makes a profit.

So the equation is x=400.

That is, 400 knife holders and 20,000 blades were sold.

The profit of factory A is 8400* (yuan.

Then the profit of factory B is 2 * 4200 = 8400 yuan.

If the number of knife holders sold by B is x, then the number of blades is 50x, according to the title, 50x*(

x=400 So factory B sold 400 knife holders and 20,000 blades.

Question 1:

First, let the number B be y, and there is a question to know: 2 3y+1=x

So 2 3y=x+1

So y=3 2(x+1).

That is, the number B is 3 2 (x+1).

Question 2: Solution: Derived from the meaning of the question:

x-(1/4x+2)-1/2[ x-(1/4x+2)]

x-1/4x-2-1/2[3/4x-2]

3/4x-2-3/8x+1

3 8x-1) km².

Answer: After two days, there was still (3 8x-1) square kilometers of land left uncultivated.

Note: x is the total area, and (1 4x+2) is the cultivated area on the first day, so [ x-(1 4x+2)] is the remaining area after the first day, and the remaining half is tilled on the second day, so 1 2 [ x-(1 4x+2)] is cultivated on the second day. Therefore, the above equation can be listed].

Question 3: Solution: Because b 0, so 4-2b 0, so |4-2b|= 4-2b

Note: Because b 0, 2b 0, -2b 0, so 4-2b 0; 】

Because a 0, b 0, so b-2a 0, so |b-2a|=-（b-2a) =-b+2a

Note: Because a 0, 2a 0, -2a 0, and because b 0, b-2a 0].

Because a 0 , so 4 + a 2 0 , so |4+a/2| =4+a/2

Note: Because a 0, a 2 0, so 4 + a 2 0].

To sum up, it is worth: |4-2b|+|b-2a|+|4+a/2|

4-2b+(-b+2a)+4+a/2

4-2b-b+2a+4+a/2

8-3b+5/2a

So |4-2b|+|b-2a|+|4+a/2| =8-3b+5/2a

The above is my answer process, that is, the idea, if you still can't understand, you can ask me for help. Full service to the end.

1) Because 1x2 = one-third 1x2x3-0x1x2) 2x3 = one-third (2x3x4-1x2x3) 3x4 = one-third (3x4x5-2x3x4) so 1x2+2x3+3x4+.100x101 =1/3（1x2x3-0x1x2）+1/3（2x3x4-1x2x3）+1/3（3x4x5-2x3x4）+.1 3 (100x101x102-99x100x101) After proposing 1 3, we get 1 3 (1x2x3-0x1x2+2x3x4-1x2x3+3x4x5-2x3x4+....+100x101x102-99x100x101) From the question 1x2+2x3+3x4=one-third x3x4x5=20, it can be seen that the one plus and one subtract in parentheses are reduced Finally, 1 3 (0x1x2+100x101x102)=1 3x100x101x102=343400 (2) is the same as the previous question: 1x2+2x3+3x4+...

n(n+1) =1/3 n(n+1)(n+2) (3) 1x2x3+2x3x4+3x4x5+..n（n+1)（n+2） =1/4(n+1)(n+2)(n+3))

1) The process of adding 3 equations:

1x2+2x3+3x4=1/3（1x2x3-0x1x2）+1/3（2x3x4-1x2x3)+1/3（3x4x5-2x3x4）

1/3（1x2x3-0x1x2+2x3x4-1x2x3+3x4x5-2x3x4)

1/3（3x4x5）=20

So 1x2+2x3+3x4+.100x101=1/3（100x101x102）=343400

2）1x2x3=1x2x3（4-0）x1/4 2x3x4=2x3x4（5-1）x1/4

From the addition of the above questions, we can get 1x2x3+2x3x4+3x4+3x4x5+.n（n+1)（n+2）= 1/4（n+1)（n+2）（n+3）

Each item is a single digit.

1+2+3+..n=1/2*n(n+1)

Each item is a two-digit number.

1*2+2*3+3*4+..n(n+1)=1/3*n(n+1)(n+2)

Each item is a three-digit number.

1*2*3+2*3*4+3*4*5+..n(n+1)(n+2)=1/4*n(n+1)(n+2)(n+3)

You solve the equation, denote x, y as m, and then substitute them into the expression 2x+y to get the range of m values.

Solution: Let the principal deposited next to the ground state be yuan.

From the meaning of the title:

Solution: 21,000 yuan.

A: ......If there is a problem with the question, the phrase "annual interest rate" should be changed to "monthly interest rate".

Solution: If the first type of loan is borrowed in total, then the second type of loan is in total (30,000) yuan.

From the meaning of the title:

Solution: $23,333.

He took out a Type A loan of $23,333.

I borrowed 6,667 yuan from B.

A: ......

1.Let the principal amount be x, and take the lead (1-20%)=420

x=21000

2.The second question is that there is a problem with the delay of the wrong.

This year's total output value is x, and the total expenditure is x-35x (1+15%)-x-35) (1-10%)=25x=

The total output value of this year is 10,000 yuan, and the total expenditure is 10,000 yuan.

Solution: If last year's total annual expenditure was X million yuan, then last year's total income was (X + 25) million yuan, this year's total output value was (1 + 15) % X million yuan, and the total expenditure was (1-10%) (X + 25) million yuan. Column equations.

1+15)% x (1-10%)(x+25)=35 gives x=230

Answer: The total output value of this year is 10,000 yuan, and the total expenditure of cherry blossom digging is 10,000 yuan.

Suppose last year's total output value is x and the total expenditure is pure y, then:

x-y=25

x=50,y=25

This year's total socks production is as follows.

The total expenditure for the year is:

Option 1: Rough processing all vegetables.

Then the profit is: 1000 * 140 = 140000 yuan Plan 2: as much as possible to rough process vegetables, and sell vegetables that have not had time to be processed.

Due to the rough processing of vegetables, 16 tons can be processed per day, so it can be processed and sold within 15 days, so the profit is: 4500 * 140 = 630,000 yuan Plan 3: part of the vegetables for fine processing, the rest of the vegetables for rough processing, exactly 15 days to complete.

Then the profit is: 7500 * 140 = 105000 yuan, so choose option 3.

The 2/3 power of 5 multiplied by the 1/2 power of 5 equals the 7/6 power of five.

3 to the 5th power multiplied by 2 to the 5th power) one-sixth square is equal to the five-sixths power of three plus the five-sixths power of two.

The original formula is equal to the sevenths of five plus the fifth-sixths of three plus the fifth-sixths of two.

Trillion = billion.

Trillion, 1.3 billion.

A: Then the GDP per capita is 10 4 yuan.

trillion yuan = 24660000000000 yuan.

1.3 billion people = 13000000000 people.

24660000000000 13000000000=19000 yuan=yuan.

trillion yuan = 100 million yuan.

trillion yuan 1.3 billion yuan.

$10 $4.

10 2 hundred dollars.

A: Then the GDP per capita is 10 200 yuan.

Per capita = trillion 1.3 billion. Wan 13

The per capita GDP is about 19,000 yuan.

GDP per capita is RMB.

GDP per capita = trillion 1.3 billion = = 19,000 yuan.