3x(2x+3y)
1. find a common multiple of either sides of the + sign...
3x
2. put it outside the brackets...
3x( )
3. find what you have to multiply the rest equation by to get the number...
2x x 3x = 6x squared
3y x 3x = 9xy
4. put it in the brackets...
3x(2x+3y)
Hope this helps :)