solve the equation by completing the square, help?

Question

i need help on this problem, i got an answer, but im not sure if its true, what answer do you get?

Solve the equation by completing the square: ^2=2 squared

3x^2+12x-9=0

Answer 1

I'd divide by 3 off the bat to make it easy:

x^2 + 4x -3 = 0

Now add 7 to both sides to get:

x^2 + 4x + 4 = 7
(x + 2)^2 = 7
x+2 = (+/-)sqrt(7)
x = sqrt(7) - 2
AND
x = -sqrt(7) - 2

Answer 2

we've been taught a distinctive approach, %. whichever is least confusing for you. c^2 + 4c - (the form right this is 0.5 the middle term, i.e. 4, then sqaured) - 7 (then - the same term in the different brackets) = 0 c^2 + 4c + 4 -7 - 4 = 0 (c+2)^2 -7 - 4 = 0 (The term in the brackets is 0.5 the middle term, offering you with a suitable sq.) (c+2)^2 -11 = 0 (c + 2 + sqrt11)(c + 2 - sqrt11)=0 (Factorise the equation to get this, a distinction of two squares) c=-2 +- sqrt11 Use the null factor regulation to get your answer.

Answer 3

x ² + 4 x - 3 = 0
( x ² + 4 x + 4 ) - 4 - 3 = 0
( x + 2 ) ² = 7
( x + 2 ) = ±√7
x = - 2 ± √7

Answer 4

x = .64575131, -4.645751 either one could be plugged in for X and give you zero. I used a TI-83 to find the zeros of the equation.

Answer 5

x=-2+sqrt(7) and -2-sqrt(7)

Answer 6

i think it's negative one