"Elimination - Solution to System of Linear Equations in Two Variables" PPT courseware for system of linear equations in two variables

Description

"Elimination - Solution to System of Linear Equations in Two Variables" PPT courseware for system of linear equations in two variables

Learning objectives of this section:

1. Be able to use the substitution method to solve systems of linear equations in two variables.

2. Preliminarily understand the basic idea of ​​solving linear equations of two variables - "elimination".

3. Through the observation and analysis of the characteristics of the unknowns in the equations, it is clear that the main idea of ​​solving the system of linear equations in two variables is "elimination", thereby promoting the transformation of the unknown into the known, cultivating the ability of observation and understanding the idea of ​​reduction.

Review the past and learn the new

1. Express y using an algebraic expression containing x:

x + y = 22

2. Express x using an algebraic expression containing y:

2x - 7y = 8

Ask students to read:

There are two unknowns in the system of linear equations of two variables. If one of the unknowns is eliminated and the system of linear equations of two variables is transformed into the familiar linear equation of one variable, we can first solve one unknown and then try to find the other unknown. This The idea of ​​reducing the number of unknown numbers from large to small and solving them one by one is called the idea of ​​elimination.

Summary:

The above solution method is to use an equation in a system of linear equations of two variables to express an unknown number with a formula containing another unknown number, and then substitute it into another equation to achieve elimination, and then obtain the solution to this system of linear equations of two variables. , this method is called substitution elimination method, or substitution method for short.

Example 1 (Learning by doing)

Solve systems of equations using substitution method

2x+3y=16 ①

x+4y=13 ②

Solution: From ②, we get x=13 - 4y ③ Is it okay to substitute ③ into ②? try it

Substituting ③ into ①, we get

2(13-4y)+3y=16

26 –8y +3y =16

-5y= -10

y=2 Is it okay to substitute y=2 into ① or ②?

Substituting y=2 into ③, we get x=5

∴The solution of the original system of equations is x=5 y=2

Keywords: Teaching courseware for systems of linear equations in two variables, teaching courseware for elimination - solutions to systems of linear equations in two variables, PPT courseware for seventh grade students in the second volume of the New People's Education Press, downloadable slideshow courseware for seventh grade mathematics, PPT for systems of linear equations in two variables Download the courseware, Download the PPT courseware on Elimination—Solution to a System of Linear Equations in Two Variables, in .ppt format

For more information about the PPT courseware "Substituting linear equations of two variables into the elimination method", please click the "Substituting the linear equations of two variables ppt into the elimination method" ppt tag.

"Solution of linear equations in two variables using the substitution method" PPT courseware for linear equations in two variables:

"Solution of linear equations in two variables by substitution method" System of linear equations in two variables PPT courseware 1. Review questions 1. What is a linear equation in two variables? System of linear equations in two variables? Solution to a system of linear equations in two variables? 2. What is the method for testing the solution of a system of linear equations in two variables? 3. The following...

"Solving System of Quadratic Equations by Substitution and Elimination Method" System of Quadratic Equations PPT Courseware:

"Solution of linear equations in two variables by substitution and elimination" PPT courseware teaching purpose of linear equations in two variables: to enable students to use the substitution and elimination method to solve linear equations in two variables. Teaching focus: the general method of solving linear equations in two variables using the substitution method. Steps. Teaching difficulties: Understand the substitution elimination method and...

File Info

Update Time: 2024-07-04

This template belongs to Mathematics courseware People's Education Press Seventh Grade Mathematics Volume 2 industry PPT template

Preview