without just giving you the solution....you need to multiply each part out of the brackets... so u need to multiply x by the 2nd bracket and +3y by the 2nd bracket.. look at it like this x(x-2y) + 3y(x-2y)... whenever you have a () () u need to do this.. hope this helps.
x(x-2y) + 3y(x-2y)... sooooo sumat like xsquared.. -2yx + 3yx -2y ... xsquared + xy - 2y ???? or i have done it completely wrong ??