若P=2a^2+5ab+3b^2,Q=2a^2-3ab+3b^2,则代入到代数式P=2P-(-P-Q)中,化简后是

Question

若P=2a^2+5ab+3b^2,Q=2a^2-3ab+3b^2,则代入到代数式P=2P-(-P-Q)中,化简后是

Answer 1

若p=a^2+3ab+b^2,q=a^2-3ab+b^2,则代数式p-｛q-2p-（-p-q）｝化简后是?
p-｛q-2p-（-p-q）｝
=p-q+2p-p-q
=2(p-q)
=2×6ab
=12ab