Question 1128512

How to complete square method of 3x^2 +6x=12
<pre>{{{matrix(1,3, 3x^2 + 6x, "=", 12)}}}
{{{matrix(1,3, 3x^2/3 + (6/3)x, "=", 12/3)}}} ----- Dividing by 3 to make LEADING COEFFICIENT, + 1.
{{{matrix(1,3, x^2 + 2x, "=", 4)}}} 
{{{matrix(1,3, x^2 + 2x + ((1/2) * 2)^2, "=", 4 + ((1/2) * 2)^2)}}} ------ Taking {{{1/2}}} of "b," SQUARING it, and then ADDING the result to both sides
{{{matrix(1,3, x^2 + 2x + (1)^2, "=", 4 + (1)^2)}}}
{{{matrix(1,3, (x + 1)^2, "=", 5)}}}
{{{matrix(1,3, sqrt((x + 1)^2), "=", " "+- sqrt(5)))}}} ----- Taking square root of both sides
{{{matrix(1,3, x + 1, "=", " "+- sqrt(5))}}}
{{{highlight_green(matrix(1,3, x, "=", " "+- sqrt(5) - 1))}}}
You can calculate that if you need APPROXIMATE solutions.