Expand (3x + 2y)² and (x - 3y)³.

$(x \pm y)^2 = x^2 \pm 2xy + y^2$, $x^2 - y^2 = (x + y)(x - y)$, $(x \pm y)^3 = x^3 \pm y^3 \pm 3xy(x \pm y)$, $x^3 \pm y^3 = (x \pm y)(x^2 \mp xy + y^2)$, and if $x + y + z = 0$ then $x^3 + y^3 + z^3 = 3xyz$.