Resposta :
(2x-3y)2+(2x+3y)2-(2x+3y)(2x-3y)
4x^2 - 12xy + 9y^2 + 4x^2 + 12xy + 9y^2 - 4x^2 + 9x^2
4x^2 + 27y^2
4x^2 - 12xy + 9y^2 + 4x^2 + 12xy + 9y^2 - 4x^2 + 9x^2
4x^2 + 27y^2