SOLUTION: Solve by completing the square {{{x^2+8 x=-15}}}

Question 143032: Solve by completing the square

Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!

Start with the given equation

Take half of the x coefficient to get (ie ).

Now square to get (ie )

Add this value to both sides

Combine like terms

Now factor to get

Take the square root of both sides

or Simplify

or Simplify Subtract from both sides in each case

So the solutions are or

Notice if we graph we can see that the roots are and . So this verifies our answer.

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