Linear equations with one unknown

Rearrange:

Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :

                     3*(2*a-5)-(21)=0 

Step by step solution :

Step  1  :

Equation at the end of step  1  :

  3 • (2a - 5) -  21  = 0 

Step  2  :

Step  3  :

Pulling out like terms :

 3.1     Pull out like factors :

   6a - 36  =   6 • (a - 6) 

Equation at the end of step  3  :

  6 • (a - 6)  = 0 

Step  4  :

Equations which are never true :

 4.1      Solve :    6   =  0

This equation has no solution.
A a non-zero constant never equals zero.

Solving a Single Variable Equation :

 4.2      Solve  :    a-6 = 0 

 Add  6  to both sides of the equation : 
                      a = 6

One solution was found :