Đáp án:
Giải thích các bước giải:
a,M+N+P
=2a^2-3a+5a^2+a-a^2+4
=2a^2+5a^2-a^2-3a+a+4
=6a^2-2a+4
b,
=2(a^2-2ab+b^2)-(a^2+2ab+b^2)-{2(a^2+2ab+b^2)-(a^2-2ab+b^2)-[(a^2-2ab+b^2)+3(a^2+2ab+b^2)-[5(a^2-2ab+b^2)-(a^2+2ab+b^2)]}
=2a^2-4ab+2b^2-a^2-2ab-b^2-{[2a^2+4ab+2b^2-a^2+2ab-b^2]-[(a^2-2ab+b^2+3a^2+6ab+3b^2)]-[5a^2-10ab+5b^2-a^2-2ab-b^2]}
=2a^2-4ab+2b^2-a^2-2ab-b^2-[(2a^2+4ab+2ab+2b^2-b^2)-(a^2+3a^2-2ab+6ab+b^2+3b^2)-(5a^2-a^2-10ab-2ab+5b^2-b^2)]
=2a^2-a^2-4ab-2ab+2b^2-b^2-[(a^2+6ab+b^2)-(4a^2+4ab+4b^2)-(4a^2-12ab+4b^2)]
=a^2-6ab+b^2-(a^2+6ab+b^2-4a^2-4ab-4b^2-4a^2+12ab-4b^2)
=a^2-6ab+b^2-(a^2-4a^2-4a^2+6ab-4ab+12ab+b^2-4b^2-4b^2)
=a^2-6ab+b^2-[(-7a^2)+14ab-7b^2]
=a^2-6ab+b^2+7a^2-14ab+7b^2
=a^2+7a^2-6ab-14ab+b^2+7b^2
=8a^2-20ab+8b^2
c,phần c thiếu đề à bn??
