Question 969850
{{{x^2-6x-4=0}}}
The first thing you want to do when completing the square is find b.
{{{ax^2+bx+c=0}}} can be used to find b in a trinomial.
when you look at the equation you were given you can see that b = -6.
now take the absolute value of b which would be 6 and divide it by 2.
This gives you 3.
Then square this number.
This gives you 9.
add 9 to each side of the equation
{{{x^2-6x+9-4=0+9}}}
This part of the equation {{{x^2-6x+9}}} can be factored into {{{(x-3)(x-3)}}}
This is the same as {{{(x-3)^2}}}.
now you have the equation {{{(x-3)^2 -4=9}}}
Solve for x
{{{(x-3)^2 -4=9}}}
{{{(x-3)^2=13}}}
{{{x-3 = +- sqrt(13)}}}
{{{x= 3 +- sqrt(13)}}}
The answers are {{{x= 3 + sqrt(13)}}} and {{{x= 3 - sqrt(13)}}}