Solve x^2 + 6x -4=0?

3 Answers

Oddman Profile
Oddman answered
You can "complete the square" by adding 13 to both sides of the equation.   x^2 + 6x - 4 = 0

  x^2 + 6x + 9 = 13    (you need to recognize that you want to end with a constant of (6/2)^2 = 9 on the left side. Starting from -4, this means you add 13.)

  (x+3)^2 = 13    (rewrite as a square. This is the form we were trying to get to.)

Now, take the square root and subtract 3
  x+3 = ±√13
  x = -3 ± √13 _____
√13 ≈ 3.60555, so x is approximately -6.60555, +0.60555.
Firefox Profile
Firefox answered
The answer is x= 6.61 , x = 0.61

what you do is you Factorise x^n+6x-4 . Which will give you ( x + 6.61 ) and ( x + 0.61 ) and then use the null factor law.

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