Question 62328
{{{3(x-2y(x+2y)-3y^2))}}} Expand the brackets working from the inside of the expression to the outside. This means the part to work on is {{{-2y(x+2y)}}}.Remember that the minus sign in front of the 2 belongs to the 2 when doing the multiplication.

{{{-2y * x = -2xy}}} and {{{-2y * 2y = -4y^2}}} so the expression is now
{{{3(x-2xy-4y^2-3y^2)}}} Simply to two y squareds inside the brackets 
{{{3(x-2xy-7y^2)}}} Now multiply the 3 by each term inside the bracket
{{{3x-6xy-21y^2}}}