3(x+2y)-3(4x-3y)-2y
There are 3 brackets to expand - the most important thing to remember is that a negative sign always belongs to the number behind it.
3(x+2y) -3(4x-3y) -2y
3*x+3*2y -3*4x - 3*-3y -2y
3x+6y -12x+9y -2y
3x-12x +6y +9y -2y
And you can finish it :)
Ask if you do not fully understand :)