Transformation equation between Na and its compounds

The reaction of sodium
4Na+O2===2Na2O
2Na + O2 = = Na2O2 (heating)
2Na+2H2O===2NaOH+H2↑
(2Na+2H2O===2Na++2OH-+H2↑)
2Na+ 2HCl===2NaCl+H2↑
( 2Na+ 2H+===2Na++H2↑)
2FeCl3+6Na+6H2O===2Fe(OH)3+6NaCl+3H2↑
(2Fe3++6Na+6H2O===2Fe(OH)3+6Na++3H2↑)
Na2O+H2O===2NaOH
( Na2O+H2O===2Na++2OH)-
2Na2O2+2H2O===4NaOH+O2↑
(2Na2O2+2H2O===4Na++4OH-+O2↑)
Na2O2+2HCl===2NaCl+H2O
(Na2O2+2H+===2Na++H2O)
2Na2O2+2CO2===2Na2CO3+O2↑
Na2CO3+2HCl=== 2NaCl +H2O+CO2↑
(CO32-+2H+=== H2O+CO2↑)
NaHCO3+ HCl===NaCl+H2O+CO2↑
(HCO3-+ H+ ===H2O+CO2↑)
2nahco3 = = Na2CO3 + CO2 ↑ + H2O (heating)
2NaOH +CuSO4===Cu(OH)2↓+Na2SO4
(2OH-+Cu2+===Cu(OH)2↓)

A binary linear system of equations, 1! And so on
The profit from purchasing vegetables by a vegetable company is shown in the following table: the profit from selling vegetables directly is 100 yuan / ton; the profit from selling vegetables after rough processing is 250 yuan; the profit from selling vegetables after finishing is 450 yuan. It is known that the company can process 6 tons of vegetables or 16 tons of vegetables every day (the two kinds of processing can not be carried out at the same time). If finishing is carried out first and then rough processing is carried out, it is required to process 140 tons of vegetables within 15 days, How much profit can the company make?

Set the finishing x tons, rough processing time for y days
140-16y = x (ton)
The solution of x 6 + y = 15 (days) is x = 60 (tons) and y = 5 (days)
So the profit is: 60x450 + 80x250 = 47000 (yuan)
A: the company made a profit of 47000 yuan

Binary linear equations of grade one in junior high school
The board of directors of a company decided to broadcast 400000 as a reward for the first, second and third prize employees. Originally, the first prize was 50000 per person, the second prize was 30000 per person, and the third prize was 20000 per person. After the number of first, second and third prizes was fixed, in order to reward the outstanding contributions to the company, the first prize was 150000 per person, and the second prize was 40000 per person, How many employees have won the first, second and third prizes?

Let x, y and Z be the first, second and third prize winners,
5x+3y+2z=40,（1）
15x+4y+z=40,（2）
（1）-2*（2）,
-25x-5y=-40,
5x+y=8,
x. Y is an integer,
x=1,y=3,z=13

What are the similarities and differences between "expressing practical problems with quadratic equation of two variables" and "expressing practical problems with quadratic equation of one variable"

Binary means that there are two unknowns in the equation, such as x + y = 10, which is a binary linear equation. Unary means that there is an unknowns in the equation, such as x + 3 = 10, which means that the highest power of the unknowns is 1. For example, the square of X equals 4 is a unary quadratic equation
Hope to help you!

The process of solving practical problems with linear equation of one variable is as follows
1. Analyze the relationship in the problem and find a relationship that can express all the meaning of the problem;
2. Set --, and list --accordingto the relation of --;
3. To solve and test the correctness and rationality of;
4. Write --
(fill in the blanks)

1. Quantity, equivalent 2. Unknown, equivalent, equation 3. Equation 4. Test, answer

A long cylindrical tube with an inner diameter of 3cm is filled with water. Now the water in the tube is gradually dropped into a cylindrical glass with an inner diameter of 8cm and a height of 1.8cm. When the glass is filled with water, the height of water in the tube decreases______ cm．

Let the height of water in the test tube drop by xcm; according to the meaning of the question: π· 1.52 · x = π· 42 × 1.8; the solution is: x = 12.8

What's the difference between the writing of the solution of bivariate linear equation and that of univariate linear equation?

There are two unknowns in binary and one unknowns in unary. Two unknowns can only be solved by two equations

It can be solved by a linear equation of two variables or a linear equation of one variable,
There is only one car for an 18 kilometer outing in Beishan. It needs to be divided into two groups. Group A takes the bus first, group B walks, and the car goes to A. group A gets off and walks, and the car returns to meet group B. the last two groups arrive at Beishan station at the same time?

Because the two groups arrive at the same time, the walking distance of the two groups is the same
The distance from a to B is 18-2x
The time from starting to meeting group B is the same as walking
[18-X+18-2X]/60=X/4
X=2
A: the distance from point a to Beishan is 2km
Method 2
Let the distance between point a and Beishan station be x, and the time for the bus to arrive at point a be y
60*y=18-x
(60-4)*y/(60+4)+y=x/4
The solution is: x = 2
Therefore, the distance between point a and Beishan station is 2km

Transformation equation between Na and its compounds