SOLUTION: how do i Solve by completing the square of x2 - 4x

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Question 24740: how do i Solve by completing the square of x2 - 4x - 5 = 0
Answer by rapaljer(4671) (Show Source):
You can put this solution on YOUR website!
Begin by adding 5 to each side to get the variables alone on the left side:

Prepare to add a number to each side of the equation that will make the left side of the equation a perfect square trinomial. I like to add a blank space to each side to set this up. Notice that in the process of completing the square, the coefficient of x^2 MUST BE 1.

Now, to make the perfect square trinomial, you need to take HALF of the coefficient of x, which is -4. Half of -4 is -2, and then SQUARE the -2, which is +4. Add PLUS 4 to each side of the equation:

Next, take the square root of each side:

Finally, add +2 to each side to isolate the x term:

This really means:
x= 2+3 = 5 OR
x= 2-3 = -1

R^2 at SCC

P.S. Of course, factoring WOULD have been a LOT easier!!!

SOLUTION: how do i Solve by completing the square of x2 - 4x - 5 = 0