Completing the Square?
Well, i have my math test this week and i don't quite get how you complete the square. Can anyone explain?
well neither of these explain it well so i'll look it up on google or something.
- 1 decade agoFavorite Answer
If you have a problem of x^2 + 6x + 5 = 0, you would know that in order to get (x + 3)^2, you would need x^2 + 6x + 9 on one side.
x^2 + 6x + 5 = 0
x^2 + 6x + 5 + 4 = 4
(x + 3)^2 = 4
- AntiApollyonLv 61 decade ago
Suppose you have an equation such as:
x^2 + 6x + 5 = 0 and you want to get (x+?)^2
You know that (x+n)^2 = x^2 + 2nx + n^2
Rewrite your equation as
x^2 + 6x = -5
Now, 2n must equal 6, so make n=3
n^2 = 3^2 = 9
Add 9 to both sides:
x^2 + 6x + 9 = -5 + 9
(x+3)^2 = 4Source(s): calebfurth: How did we both arbitrarily pick the exact same example problem?