化简 (1)m-(5m-3n)+3(2m-n); (2)3ab-[2a2-(b2-3ab)-a2].

问题描述:

化简
(1)m-(5m-3n)+3(2m-n);
(2)3ab-[2a2-(b2-3ab)-a2].

(1)原式=m-5m+3n+6m-3n
=2m;
(2)原式=3ab-2a2+b2-3ab+a2
=-a2+b2