Solution - Linear equations with one unknown

Step by step solution :

Step  1  :

Equation at the end of step  1  :

  (r - 3) • (r + 6)  = 0 

Step  2  :

Theory - Roots of a product :

 2.1    A product of several terms equals zero. 

 When a product of two or more terms equals zero, then at least one of the terms must be zero. 

 We shall now solve each term = 0 separately 

 In other words, we are going to solve as many equations as there are terms in the product 

 Any solution of term = 0 solves product = 0 as well.

Solving a Single Variable Equation :

 2.2      Solve  :    r-3 = 0 

 Add  3  to both sides of the equation : 
                      r = 3

Solving a Single Variable Equation :

 2.3      Solve  :    r+6 = 0 

 Subtract  6  from both sides of the equation : 
                      r = -6

Two solutions were found :

1.  r = -6
2.  r = 3