Question

please help.... x^2+2x-5=0 solve by completing the square

Answer 1

Well, do it.

x^2 + 2x + ______ = 5 + ______

Fill in the blanks.

Answer 2

I dont know how?

Answer 3

@tkhunny

Answer 4

Separate the 5 from the rest of the eqatuion and put it on the other side of the equal sign. Take half the x term (half of 2 is 1) and square the 1 to get 1. Add the 1 to both sides of the equation, which gives you x^2 + 2x + 1 = 5 + 1. Now, what did you do to get the 1 in the constant position? Squared the 1. Right? So the left side of the equation looks like this: (x +1)^2 and the right side is a 6. (x + 1)^2 = 6. Now take the square root of both sides, leaving x + 1 = square root of 6. Subtract the 1 and that leaves x = -1 +/- sq rt 6. Do you get that?

Answer 5

You must exploit this principle.

\((a+b)^{2} = a^{2} + 2ab + b^{2}\)

That is all you are doing.

Please note that you have shown no work on this thread. You MUST do better than that.