问题
解答题
计算:
(1)(a2+3)(a-2)-a(a2-2a-2);
(2)(2m+n)(2m-n)+(m+n)2-2(2m2-mn).
答案
(1)原式=a3-2a2+3a-6-a3+2a2+2a
=5a-6;
(2)原式=4m2-n2+m2+2mn+n2-4m2+2mn
=m2+4mn.
计算:
(1)(a2+3)(a-2)-a(a2-2a-2);
(2)(2m+n)(2m-n)+(m+n)2-2(2m2-mn).
(1)原式=a3-2a2+3a-6-a3+2a2+2a
=5a-6;
(2)原式=4m2-n2+m2+2mn+n2-4m2+2mn
=m2+4mn.