Steps of solving linear equation with one variable (five steps) What are the five steps

Steps of solving linear equation with one variable (five steps) What are the five steps

1. Transference
2. Merge congeners
These are the two most critical steps in solving the equation
The other is Pediatrics, what is the unknown coefficient of 1 and so on small case
Just these two steps can make up hundreds of questions for you, but they can't be separated from each other. As long as you have a clear understanding of the principle and a real understanding, these will be easily solved
The key is to practice more
Practice to the general equation, the number is not complex, can be calculated by mouth
Do it! You can't learn mathematics well without hardship. The more you study mathematics, the smarter you will be. I think so, but the smarter you learn, the smarter you will be
Although the equation of one variable is simple, it is the foundation. If your solution is too dogmatic, you will never want to learn mathematics well in your life
Mathematics must lay a good foundation, strengthen the sense of numbers, or after the math class will be like listening to the book of heaven

Write the procedure to solve the equation of degree one variable
The students of the school's science and technology group took a bus to the distant provincial capital to participate in the science and technology exhibition. Xiao Ming had to leave for half an hour because of something, but he took a faster high-speed bus to catch up with everyone at the same place. The speed of the bus and the high-speed bus is 60km / h and 80km / h respectively, How many hours after departure can the high-speed bus catch up with the bus? How far is it from the starting point?

Set X hours to catch the bus
60*x+60*0.5=80*x
30=20x
x=1.5
So 1.5 hours
The distance from the starting point is 80 * 1.5 = 120 km

Is the solution of linear equations of one variable unique

Yes, the only one

Solution of linear equations with elimination

8.2 elimination solution of binary linear equations (1) there are two unknowns in the binary linear equations in the seventh grade mathematics volume II (people's Education Press). If one of the unknowns is eliminated and the binary linear equations are transformed into the familiar one, we can solve an unknown number first, Today's assignment: exercise 8.2, question 2, Page 103 of the textbook * Wu Xiaoqiang's attitude decides everything! The one who knows is not as good as the one who knows, The learning objectives of this section: 1. Be able to use substitution method to solve binary linear equations. 2. Have a preliminary understanding of the basic idea of solving binary linear equations - "elimination". 3. Through the observation and analysis of the characteristics of unknowns in equations, it is clear that the main idea of solving binary linear equations is "elimination", so as to promote the transformation from unknown to known, 1. Express Y: x + y = 22 2 with the algebraic formula containing x, and express X: 2x - 7Y = 8 with the algebraic formula containing y. in basketball league matches, each team has to win one game and get 2 points. If a team wants to win 40 points in all 22 games in order to win a better place, it has to win 40 points, Then, what are the number of wins and losses of this team? Let's set the winning x field and the negative y field. ① ② ③ is a one variable linear equation, and I believe everyone can solve it. Then, according to the above tips, can you solve the equations? From ① we can get: if we change y in ② into y, we can get ③ if we set the winning x field, we can review and think about the relationship between the above equations and the equations? ③ 40) 22 (2 = - + x x) the above solution is to use an equation in the system of linear equations of two variables to express an unknown number with an equation containing another unknown number, and then substitute it into another equation to realize elimination, so as to obtain the solution of the system of linear equations of two variables. This method is called substitution elimination method, For short, the substitution method is summarized as follows: using the substitution method to solve the system of equations 2x + 3Y = 16, ① x + 4Y = 13, ② the solution of the original system of equations is x = 5, y = 2, example 1 (learning in practice) from ②, x = 13 - 4Y, ③ to ①, 2 (13 - 4Y) + 3Y = 16, 26 - 8y + 3Y = 16 - 5Y = - 10, y = 2, y = 2 to ③, Can we get x = 5 and substitute 3 for 2? Can we try substituting y = 2 for 1 or 2? Can we substitute the solution into the original equations, According to the meaning of the question, the following equations can be formulated: ① you get: substitute: ③ you get: x = 20000 substitute: y = 50000 ③ answer: these disinfectants should be divided into 20000 large bottles and 50000 small bottles, The ratio of the sales quantity (calculated by bottle) of a disinfectant in large bottle (500g) and small bottle (250g) is 22.5 tons of the disinfectant produced by a factory every day. How many bottles should these disinfectants be packed in large and small bottles? ① ② í ì = + = 22500000 250 500 25 y x y x binary linear equation is transformed and substituted into y = 50000 x = 20000 to get x unitary linear equation Instead of Y, The process of solving the equations above the elimination of the unknown y can be represented by the following block diagram: discuss the substitution elimination method in class again: y = 2x (1) x + y = 12 (2) x = - y-52 4x + 3Y = 65 (3) x + y = 11 X-Y = 7 (4) 3x-2y = 9 x + 2Y = 3 x = 4 y = 8 x = 5 y = 15 x = 9 y = 2 x = 3 y = 0 do you have the right solution? 1= According to the known conditions, the system of equations can be listed as follows: 2m + n = 1 3M – 2 n = 1 ① ② from ①: substitute ③ into ②: n = 1 – 2m ③ 3M – 2 (1 – 2m) = 1 3M – 2 + 4m = 1 7m = 3 substitute m into ③: 3. There are thirty-five chickens and rabbits in the same cage and ninety-four chickens and rabbits in the same cage, There are y rabbits. Can you list the equations? X + y = 352