(3a+2b)X(2a+b)—(2b+a)X(b+a)
=6a^2+3ab+4ab+2b^2-2b^2-2ab-ab-a^2
=5a^2+4ab
(3b+2a)X(b+2a)—(3bX2a)
=3b^2+6ab+2ab+4a^2-6ab
=3b^2+2ab+4a^2
(3a+2b)X(2a+b)—(2b+a)X(b+a)
=6a^2+3ab+4ab+2b^2-2b^2-2ab-ab-a^2
=5a^2+4ab
(3b+2a)X(b+2a)—(3bX2a)
=3b^2+6ab+2ab+4a^2-6ab
=3b^2+2ab+4a^2