Упростите выражение.
(x-3)^2-8=x^2-6x+9-8=x^2-6x+1 (2x-3y)^2+(4x+2y)^2=4x^2-12xy+9y^2+16x^2+16xy+4y^2=20x^2+4xy+13y^2 (6a-b)^2-(9a-b)(4a+2b)=36a^2-12ab+b^2-(36a^2+18ab-4ab-2b^2)=36a^2-12ab+b^2-36a^2-18ab+4ab+2b^2=-2ab+3b^2=b(3b-2a)