How do we expand (3y-2)^2?

(3y-2)^2=(3y-2)(3y-2)You're basically multiplying 3y-2 by itself.Let's start with the 3x in the first bracket.3y x 3y + 3y x (-2)=9y^2-6yNow let's move on to the -2 in the first bracket.-2 x 3y + (-2) x (-2)=-6y + 4Add them both together.9y^2-6y + (-6y)+4=9y^2-6y-6y+4=9y^2-12y+4