SOLUTION: 4rē-28r=-49. Solve by completing the square

Algebra.Com
Question 651875: 4rē-28r=-49. Solve by completing the square
Answer by Edwin McCravy(20064)   (Show Source): You can put this solution on YOUR website!
4rē-28r = -49

Divide through by the coefficient of rē which is 4:

rē - r = 

  rē - 7r = 

To the side 

1.  Multiply the coefficient of r, which is -7, by ,
getting 
2.  Square that result:   = 
3.  Add that number to both sides of the equation:

  rē - 7r +  =  + 

Factor the left side, combine the terms on the right

 (r - )(r - ) = 0

Use the zero-factor property:

   r -  = 0;  r -  = 0

      r = ;  r = 

Both are the same, so

 is a double solution or "a root of multiplicity 2".

Edwin
RELATED QUESTIONS

solve this equation by completing the square -4r^2+21r=r+13 (answered by stanbon)
Solve the quadratic equation by completing the square.... (answered by KMST)
Solve by completing the square... (answered by stanbon)
m^2-49/2m=1/2 solve by completing the... (answered by unlockmath)
Solve by completing the square. m^2-(49/2)m=1/2 the solutions are? please help me... (answered by drk)
Solve 7x^2+28x=49 by completing the square. I know you use the formula (b/2)^2... (answered by jim_thompson5910)
Solve by completing the square : W^2-4W =... (answered by )
Solve by completing the square. z^2 + z =... (answered by longjonsilver)
{{{2x^2-3x+1=0}}}Solve by completing the... (answered by Earlsdon)