6x^2=12x-20 subtract 12x from both sides
6x^2-12x=-20 divide both sides by 6
x^2-2x=-10/3 halve the linear coefficient, square it, and add it to both sides, in this case 1
x^2-2x+1=3/3-10/3 now the left sides is a perfect square
(x-1)^2=-7/3 take the square root of both sides
x-1=±i√(7/3) add 1 to both sides
x=1±i√(7/3)
*note that these are imaginary solutions, as the original equation is never true, or if you prefer, 6x^2-12x+20 is never equal to zero.
