Enter an equation or problem
Camera input is not recognized!

Solution - Factoring binomials using the difference of squares

x=negativeroot[27]6=-1.0686
x=negativeroot[27]{6}=-1.0686
x=0
x=0

Step by Step Solution

Rearrange:

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

                     x^28-(-6*x)=0 

Step by step solution :

Step  1  :

Step  2  :

Pulling out like terms :

 2.1     Pull out like factors :

   x28 + 6x  =   x • (x27 + 6) 

Trying to factor as a Sum of Cubes :

 2.2      Factoring:  x27 + 6 

Theory : A sum of two perfect cubes,  a3 + b3 can be factored into  :
             (a+b) • (a2-ab+b2)
Proof  : (a+b) • (a2-ab+b2) =
    a3-a2b+ab2+ba2-b2a+b3 =
    a3+(a2b-ba2)+(ab2-b2a)+b3=
    a3+0+0+b3=
    a3+b3


Check :  6  is not a cube !!
Ruling : Binomial can not be factored as the difference of two perfect cubes

Equation at the end of step  2  :

  x • (x27 + 6)  = 0 

Step  3  :

Theory - Roots of a product :

 3.1    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 :

 3.2      Solve  :    x = 0 

 
Solution is  x = 0

Solving a Single Variable Equation :

 3.3      Solve  :    x27+6 = 0 

 
Subtract  6  from both sides of the equation : 
 
                     x27 = -6
                     x  =  27th root of (-6) 

 
Negative numbers have real 27th roots.
 27th root of (-6) = 27 -1• 6  = 27 -1 27 6  =(-1)•27 6 

The equation has one real solution, a negative number This solution is  x = negative 27th root of 6 = -1.0686

Two solutions were found :

  1.  x = negative 27th root of 6 = -1.0686
  2.  x = 0

Why learn this

Latest Related Drills Solved