Solution - Adding, subtracting and finding the least common multiple

Reformatting the input :

Changes made to your input should not affect the solution:

 (1): "x8"   was replaced by   "x^8". 

Rearrange:

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

                     2/9-(4/x^8)=0 

Step by step solution :

Step  1  :

             4
 Simplify   ——
            x8

Equation at the end of step  1  :

  2     4
  — -  ——  = 0 
  9    x8

Step  2  :

            2
 Simplify   —
            9

Equation at the end of step  2  :

  2     4
  — -  ——  = 0 
  9    x8

Step  3  :

Calculating the Least Common Multiple :

 3.1    Find the Least Common Multiple

      The left denominator is :       9 

      The right denominator is :       x⁸ 

      Least Common Multiple:
      9x⁸ 

Calculating Multipliers :

 3.2    Calculate multipliers for the two fractions


    Denote the Least Common Multiple by  L.C.M 
    Denote the Left Multiplier by  Left_M 
    Denote the Right Multiplier by  Right_M 
    Denote the Left Deniminator by  L_Deno 
    Denote the Right Multiplier by  R_Deno 

   Left_M = L.C.M / L_Deno = x⁸

   Right_M = L.C.M / R_Deno = 9

Making Equivalent Fractions :

 3.3      Rewrite the two fractions into equivalent fractions

Two fractions are called equivalent if they have the same numeric value.

For example :  1/2   and  2/4  are equivalent,  y/(y+1)²   and  (y²+y)/(y+1)³  are equivalent as well.

To calculate equivalent fraction , multiply the Numerator of each fraction, by its respective Multiplier.

   L. Mult. • L. Num.      2 • x8
   ——————————————————  =   ——————
         L.C.M              9x8  

   R. Mult. • R. Num.      4 • 9
   ——————————————————  =   —————
         L.C.M              9x8 

Adding fractions that have a common denominator :

 3.4       Adding up the two equivalent fractions
Add the two equivalent fractions which now have a common denominator

Combine the numerators together, put the sum or difference over the common denominator then reduce to lowest terms if possible:

 2 • x8 - (4 • 9)     2x8 - 36
 ————————————————  =  ————————
       9x8              9x8   

Step  4  :

Pulling out like terms :

 4.1     Pull out like factors :

   2x⁸ - 36  =   2 • (x⁸ - 18) 

Trying to factor as a Difference of Squares :

 4.2      Factoring:  x⁸ - 18 

Theory : A difference of two perfect squares,  A² - B²  can be factored into  (A+B) • (A-B)

Proof :  (A+B) • (A-B) =
         A² - AB + BA - B² =
         A² - AB + AB - B² =
         A² - B²

Note :  AB = BA is the commutative property of multiplication.

Note :  - AB + AB equals zero and is therefore eliminated from the expression.

Check : 18 is not a square !!

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

Polynomial Roots Calculator :

 4.3    Find roots (zeroes) of :       F(x) = x⁸ - 18
Polynomial Roots Calculator is a set of methods aimed at finding values of  x  for which   F(x)=0  

Rational Roots Test is one of the above mentioned tools. It would only find Rational Roots that is numbers  x  which can be expressed as the quotient of two integers

The Rational Root Theorem states that if a polynomial zeroes for a rational number  P/Q   then  P  is a factor of the Trailing Constant and  Q  is a factor of the Leading Coefficient

In this case, the Leading Coefficient is  1  and the Trailing Constant is  -18.

 The factor(s) are:

of the Leading Coefficient :  1
 of the Trailing Constant :  1 ,2 ,3 ,6 ,9 ,18

 Let us test ....

Polynomial Roots Calculator found no rational roots

Equation at the end of step  4  :

  2 • (x8 - 18)
  —————————————  = 0 
       9x8     

Step  5  :

When a fraction equals zero :

 5.1    When a fraction equals zero ...

Where a fraction equals zero, its numerator, the part which is above the fraction line, must equal zero.

Now,to get rid of the denominator, Tiger multiplys both sides of the equation by the denominator.

Here's how:

  2•(x8-18)
  ————————— • 9x8 = 0 • 9x8
     9x8   

Now, on the left hand side, the  9x⁸  cancels out the denominator, while, on the right hand side, zero times anything is still zero.

The equation now takes the shape :
   2  •  (x⁸-18)  = 0

Equations which are never true :

 5.2      Solve :    2   =  0

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

Solving a Single Variable Equation :

 5.3      Solve  :    x⁸-18 = 0 

 Add  18  to both sides of the equation : 
                      x⁸ = 18
                     x  =  8th root of (18) 

 The equation has two real solutions  
 These solutions are  x = ± 8th root of 18 = ± 1.4352  
 

Two solutions were found :