Solution - Adding, subtracting and finding the least common multiple

Reformatting the input :

Changes made to your input should not affect the solution:

(1): "0.25" was replaced by "(25/100)". 3 more similar replacement(s)

Step by step solution :

Step  1  :

            1
 Simplify   —
            4

Equation at the end of step  1  :

     9        19     1
  ((——•(x2))-(——•x))+—  = 0 
    10        10     4

Step  2  :

            19
 Simplify   ——
            10

Equation at the end of step  2  :

     9        19     1
  ((——•(x2))-(——•x))+—  = 0 
    10        10     4
 Step  3  :
             9
 Simplify   ——
            10

Equation at the end of step  3  :

     9          19x     1
  ((—— • x2) -  ———) +  —  = 0 
    10          10      4

Step  4  :

Equation at the end of step  4  :

   9x2    19x     1
  (——— -  ———) +  —  = 0 
   10     10      4

Step  5  :

Adding fractions which have a common denominator :

 5.1       Adding fractions which have a common denominator
Combine the numerators together, put the sum or difference over the common denominator then reduce to lowest terms if possible:

 9x2 - (19x)     9x2 - 19x
 ———————————  =  —————————
     10             10    

Equation at the end of step  5  :

  (9x2 - 19x)    1
  ——————————— +  —  = 0 
      10         4

Step  6  :

Step  7  :

Pulling out like terms :

 7.1     Pull out like factors :

   9x² - 19x  =   x • (9x - 19) 

Calculating the Least Common Multiple :

 7.2    Find the Least Common Multiple

      The left denominator is :       10 

      The right denominator is :       4 

      Least Common Multiple:
      20 

Calculating Multipliers :

 7.3    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 = 2

   Right_M = L.C.M / R_Deno = 5

Making Equivalent Fractions :

 7.4      Rewrite the two fractions into equivalent fractions

   L. Mult. • L. Num.      x • (9x-19) • 2
   ——————————————————  =   ———————————————
         L.C.M                   20       

   R. Mult. • R. Num.       5
   ——————————————————  =   ——
         L.C.M             20

Adding fractions that have a common denominator :

 7.5       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:

 x • (9x-19) • 2 + 5     18x2 - 38x + 5
 ———————————————————  =  ——————————————
         20                    20      

Trying to factor by splitting the middle term

 7.6     Factoring  18x² - 38x + 5 

The first term is,  18x²  its coefficient is  18 .
The middle term is,  -38x  its coefficient is  -38 .
The last term, "the constant", is  +5 

Step-1 : Multiply the coefficient of the first term by the constant   18 • 5 = 90 

Step-2 : Find two factors of  90  whose sum equals the coefficient of the middle term, which is   -38 .

For tidiness, printing of 18 lines which failed to find two such factors, was suppressed

Observation : No two such factors can be found !!
Conclusion : Trinomial can not be factored

Equation at the end of step  7  :

  18x2 - 38x + 5
  ——————————————  = 0 
        20      

Step  8  :

When a fraction equals zero :

 8.1    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:

  18x2-38x+5
  —————————— • 20 = 0 • 20
      20    

Now, on the left hand side, the  20  cancels out the denominator, while, on the right hand side, zero times anything is still zero.

The equation now takes the shape :
   18x²-38x+5  = 0

Parabola, Finding the Vertex :

 8.2      Find the Vertex of   y = 18x²-38x+5

Parabolas have a highest or a lowest point called the Vertex .   Our parabola opens up and accordingly has a lowest point (AKA absolute minimum) .   We know this even before plotting  "y"  because the coefficient of the first term, 18 , is positive (greater than zero). 

 Each parabola has a vertical line of symmetry that passes through its vertex. Because of this symmetry, the line of symmetry would, for example, pass through the midpoint of the two  x -intercepts (roots or solutions) of the parabola. That is, if the parabola has indeed two real solutions. 

 Parabolas can model many real life situations, such as the height above ground, of an object thrown upward, after some period of time. The vertex of the parabola can provide us with information, such as the maximum height that object, thrown upwards, can reach. For this reason we want to be able to find the coordinates of the vertex. 

 For any parabola,Ax²+Bx+C,the  x -coordinate of the vertex is given by  -B/(2A) . In our case the  x  coordinate is   1.0556  

 Plugging into the parabola formula   1.0556  for  x  we can calculate the  y -coordinate : 
  y = 18.0 * 1.06 * 1.06 - 38.0 * 1.06 + 5.0
or   y = -15.056

Parabola, Graphing Vertex and X-Intercepts :

Root plot for :  y = 18x²-38x+5
Axis of Symmetry (dashed)  {x}={ 1.06} 
Vertex at  {x,y} = { 1.06,-15.06} 
 x -Intercepts (Roots) :
Root 1 at  {x,y} = { 0.14, 0.00} 
Root 2 at  {x,y} = { 1.97, 0.00} 

Solve Quadratic Equation by Completing The Square

 8.3     Solving   18x²-38x+5 = 0 by Completing The Square .

 Divide both sides of the equation by  18  to have 1 as the coefficient of the first term :
   x²-(19/9)x+(5/18) = 0

Subtract  5/18  from both side of the equation :
   x²-(19/9)x = -5/18

Now the clever bit: Take the coefficient of  x , which is  19/9 , divide by two, giving  19/18 , and finally square it giving  361/324 

Add  361/324  to both sides of the equation :
  On the right hand side we have :
   -5/18  +  361/324   The common denominator of the two fractions is  324   Adding  (-90/324)+(361/324)  gives  271/324 
  So adding to both sides we finally get :
   x²-(19/9)x+(361/324) = 271/324

Adding  361/324  has completed the left hand side into a perfect square :
   x²-(19/9)x+(361/324)  =
   (x-(19/18)) • (x-(19/18))  =
  (x-(19/18))²
Things which are equal to the same thing are also equal to one another. Since
   x²-(19/9)x+(361/324) = 271/324 and
   x²-(19/9)x+(361/324) = (x-(19/18))²
then, according to the law of transitivity,
   (x-(19/18))² = 271/324

We'll refer to this Equation as  Eq. #8.3.1  

The Square Root Principle says that When two things are equal, their square roots are equal.

Note that the square root of
   (x-(19/18))²   is
   (x-(19/18))^2/2 =
  (x-(19/18))¹ =
   x-(19/18)

Now, applying the Square Root Principle to  Eq. #8.3.1  we get:
   x-(19/18) = √ 271/324

Add  19/18  to both sides to obtain:
   x = 19/18 + √ 271/324

Since a square root has two values, one positive and the other negative
   x² - (19/9)x + (5/18) = 0
   has two solutions:
  x = 19/18 + √ 271/324
   or
  x = 19/18 - √ 271/324

Note that  √ 271/324 can be written as
  √ 271  / √ 324   which is √ 271  / 18

Solve Quadratic Equation using the Quadratic Formula

 8.4     Solving    18x²-38x+5 = 0 by the Quadratic Formula .

 According to the Quadratic Formula,  x  , the solution for   Ax²+Bx+C  = 0  , where  A, B  and  C  are numbers, often called coefficients, is given by :
                                     
            - B  ±  √ B²-4AC
  x =   ————————
                      2A

  In our case,  A   =     18
                      B   =   -38
                      C   =   5

Accordingly,  B²  -  4AC   =
                     1444 - 360 =
                     1084

Applying the quadratic formula :

               38 ± √ 1084
   x  =    ——————
                      36

Can  √ 1084 be simplified ?

Yes!   The prime factorization of  1084   is
   2•2•271 
To be able to remove something from under the radical, there have to be  2  instances of it (because we are taking a square i.e. second root).

√ 1084   =  √ 2•2•271   =
                ±  2 • √ 271

  √ 271   , rounded to 4 decimal digits, is  16.4621
 So now we are looking at:
           x  =  ( 38 ± 2 •  16.462 ) / 36

Two real solutions:

 x =(38+√1084)/36=(19+√ 271 )/18= 1.970

or:

 x =(38-√1084)/36=(19-√ 271 )/18= 0.141

Two solutions were found :

1.  x =(38-√1084)/36=(19-√ 271 )/18= 0.141
2.  x =(38+√1084)/36=(19+√ 271 )/18= 1.970