Question 43474
I'm not sure if you know this, but {{{(a-b)^2 = a^2 - 2ab + b^2}}}. Therefore,

{{{(2x-3)^2}}}
{{{(2x)^2 - 2*2x*3 + 3^2}}}
{{{4x^2 - 4x*3 + 9}}}
{{{4x^2 - 12x + 9}}}

If nobody has taught you the above formula, consider this solution instead:

{{{(2x-3)^2}}}
{{{(2x-3)(2x-3)}}}
{{{2x*2x + 2x*-3 + -3*2x + -3*-3}}}
{{{4x^2 - 6x - 6x + 9}}}
{{{4x^2 - 12x + 9}}}