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Solution - Factoring binomials using the difference of squares

x=213thfo(0.444)=0.99620
x=213throotof(-0.444)=-0.99620

Step by Step Solution

Step by step solution :

Step  1  :

Equation at the end of step  1  :

  (0 -  (32x212 • x)) -  4  = 0 

Step  2  :

Step  3  :

Pulling out like terms :

 3.1     Pull out like factors :

   -9x213 - 4  =   -1 • (9x213 + 4) 

Trying to factor as a Sum of Cubes :

 3.2      Factoring:  9x213 + 4 

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 :  9  is not a cube !!

Ruling : Binomial can not be factored as the difference of two perfect cubes

Equation at the end of step  3  :

  -9x213 - 4  = 0 

Step  4  :

Solving a Single Variable Equation :

 4.1      Solve  :    -9x213-4 = 0 

 
Add  4  to both sides of the equation : 
 
                     -9x213 = 4
Multiply both sides of the equation by (-1) :  9x213 = -4


Divide both sides of the equation by 9:
                     x213 = -4/9 = -0.444
                     x  =  213th root of (-4/9) 

 
Negative numbers have real 213th roots.
 213th root of (-4/9) = 213 -1• 4/9  = 213 -1 213 4/9  =(-1)•213 4/9 

The equation has one real solution, a negative number This solution is  x = 213th root of (-0.444) = -0.99620

One solution was found :

                   x = 213th root of (-0.444) = -0.99620

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