Question 138827
{{{(ay-b)^2 }}} = {{{a^2y^2 - 2aby + b^2}}}

You are given {{{4y^2-12y = -13}}}
In this equation, a is 2  (since 4 = 2^2)
And {{{-12 = -2ab}}} = {{{-12 = -4b}}} = {{{3 = b}}}

{{{4y^2-12y +9 = -13 + 9}}}
{{{(2y-3)^2 = -4}}}
{{{2y-3 = +-2i}}}

{{{y = (3+2i)/2}}} and 
{{{y = (3-2i)/2}}}