To expand the brackets you need to multiply each item inside with the number on the outside. The first bracket is expanded as follows: 5x = 5x, 53 = 15, therefore 5x + 15. There is a minus sign in front of the second bracket, it is important to remember this when expanding the bracket and to remember the rule that when a minus number is multiplied by a minus number the result is always positive. The second bracket: -3y = -3y, -3-2 = 6, therefore -3y + 6. When this is put together you get 5x + 15 - 3y + 6. This can be simplified further by adding together the similar items: 15 + 6 = 21. This leaves a final answer of 5x - 3y + 21.