Please answer the question from the attachment.
Since all of the variables are y^3, all we have to do is the addition and subtraction of the whole numbers...2y^3 - 3y^3 + 3y^3 - 4y^3 =-2y^3***Notice that the -3y^3 and 3y^3 just cancel out so all you have to do is the 2-4 = -2 Piece of cake :)