2006-06-12 06:51:41 · 4 answers · asked by jenniffer m 2 in Science & Mathematics ➔ Mathematics
y = x² - 4x - 5
Simplify -5 = 4 - 9 to complete the square
y = x² - 4x + 4 - 9
Simplify the square
y = (x - 2)² - 9
^_^
2006-06-12 23:24:25 · answer #1 · answered by kevin! 5 · 0⤊ 1⤋
First you have no coefficient on x^2, so a will be 1.
Realize that.
(x - n)(x - n) = x^2 - 2nx + n^2
So -2n = -4,
n = 2
Expanding out you have:
= (x - 2)(x - 2)
= x^2 - 4x + 4
But your equation for y is:
x^2 - 4x - 5
This is:
(x^2 - 4x + 4) - 9
So your final answer is:
y = (x - 2)^2 - 9
2006-06-12 07:19:08 · answer #2 · answered by Puzzling 7 · 0⤊ 0⤋
y=(1)(x-2)^2+(-9)
2006-06-12 06:55:40 · answer #3 · answered by Anonymous · 0⤊ 0⤋
y = x^2 - 4x - 5
y = (x^2 - 4x) - 5
y = (x^2 - 4x + 4 - 4) - 5
y = ((x - 2)^2 - 4) - 5
y = (x - 2)^2 - 4 - 5
y = (x - 2)^2 - 9
2006-06-12 07:16:09 · answer #4 · answered by Sherman81 6 · 0⤊ 0⤋