SOLUTION: Completing the square. 1.)x^2+6x=7 2.) x^2+8x=9 3.) 9x^2+19x=-8 (solve by completing the square an coefficient of x^2 is 1) I'm looking for the processes of these. The

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Question 1026796: Completing the square.
1.)x^2+6x=7
2.) x^2+8x=9
3.) 9x^2+19x=-8 (solve by completing the square an coefficient of x^2 is 1)
I'm looking for the processes of these. The book examples don't help.

Found 2 solutions by ikleyn, MathTherapy:
Answer by ikleyn(52781)   (Show Source): You can put this solution on YOUR website!
.
Completing the square.
1.)x^2+6x=7
2.) x^2+8x=9
3.) 9x^2+19x=-8 (solve by completing the square an coefficient of x^2 is 1)
I'm looking for the processes of these. The book examples don't help.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 

1)  = ,

    = 

    = ,      ( I added and distracted 9 )

    =               (  =  )

    = ,                 ( Now take the square root from both sides )

    = +/- 4,

   x = 3 +/- 4,

   x = 7 and/or x = -1.


2)  x^2+8x=9      is exactly the same.  Do it yourself.

3)  9x^2+19x=-8   I suspect you missed something here.


Answer by MathTherapy(10552)   (Show Source): You can put this solution on YOUR website!
Completing the square.
1.)x^2+6x=7
2.) x^2+8x=9
3.) 9x^2+19x=-8 (solve by completing the square an coefficient of x^2 is 1)
I'm looking for the processes of these. The book examples don't help.


 ------ Adding  the value of b, and then squaring the result

 ------ Adding  ------ Substituting + 6 for b

 





 ------- Taking square root of both sides









Follow the above steps and you should be able to do number 2

Number 3 can get quite MESSY. Did you really mean: , or something else? If it's correct, factor

out 9 on both sides to get a coefficient of 1 on , and once again, follow the steps in number 1 

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