Solve the problem by completing the square.
x^2 - 2x - 3 = 0
2007-03-13 14:00:39 · 5 answers · asked by Anonymous in Education & Reference ➔ Homework Help
x^2 - 2x -3 = 0
add three to both sides to get...
x^2 - 2x = 3
To complete the square, take half the coefficient of x and square it.....half of 2 is 1, squared is 1, so add 1 to both sides:
x^2 - 2x + 1 = 3 +1
x^2 - 2x + 1 = 4 now factor x^2 - 2x +1 to get...
(x - 1)^2 = 4, then square root both sides....
(x - 1) = +/- 2, now add one to both sides to get..
x = 1 +/- 2----->3 or -1
2007-03-13 14:08:19 · answer #1 · answered by garyhorne55 1 · 1⤊ 0⤋
You never need to complete the square to solve a quadratic, but it's necessary in other areas such as analytic geometry.
I'll give you the steps - email me if you need further explanation of them.
x^2 - 2x - 3 = 0
x^2 - 2x = 3
Take 2, cut it in half (1) and square it (1). Add that to both sides:
x^2 - 2x + 1 = 3 + 1
(x - 1)^2 = 4
x - 1 = +/- sqrt(4) = +/- 2
x = 1 +/- 2
So x = 3 or x = -1.
2007-03-13 14:10:32 · answer #2 · answered by Anonymous · 0⤊ 0⤋
17
2007-03-13 14:02:05 · answer #3 · answered by .K. 3 · 0⤊ 1⤋
(x-3)(x+1)=0
(x-3)=0 (x+1)=0
x=3 x=-1
you don't need to complete the square...EVER. Factor or use quadratic formula.
And how the **** do you get 17?
2007-03-13 14:02:37 · answer #4 · answered by Anonymous · 0⤊ 1⤋
360 na its 17
2007-03-13 14:03:24 · answer #5 · answered by Anonymous · 0⤊ 1⤋