LINEAR EQUATION IN ONE VARIABLE | REVISION NOTES | CLASS 8

 In the 7th Class, we had learnt about Linear Equations and their Solutions. However, we will review these facts again and also take up new types of linear equations 

Equation

An equation is a statement of equality of two algebraic expressions involving one or more unknown quantities, called variables. 

An equation involving only linear polynomials is called a linear equations 

Some example of linear equations : 

 Rule for solving a linear equation

1. we can add the same number on both sides of the equation.
2. we can subtract the same number from both sides of the equation.
3. we can multiply both sides of the equation by the same non zero number.
4. if  then  This process is called cross multiplication . 
5. Any term of an equation may be taken to the other side with a change in its sign This process is called transposition Thus , 

Example 

Q.1 Solve : 8x = 20 + 3x.

Solution : 

 

 

                          

                         

Q.2 Solve : 

Solution : 

                   (Cross Multiplication )

                 

                 

                 

                 

Q.3 Solve: 

Solution : 

                

                

                

                

               

Q.4 Solve :

 

Solution :    

                   

                   

                   

                  

                   

                   Hence, 

Q.5 Solve : 

Solution : 

                

               

                

                 

                 

               Hence ,

Q.6 Solve : 

 

Solution : 

 

 

APPLICATIONS OF LINEAR EQUATIONS