远山竹影
幼苗
共回答了24个问题采纳率:95.8% 举报
1.1/2a[xy(xy+4)+4]
2.-2x^n(x^2+2)
3.9[(m+n)^2-(4/3)^2(m-n)^2]
=9(7/3m-1/3n)(7/3n-1/3m)
5.1/2 a^2(2a-x)^2-1/4 a(2a-x)^3
=1/4a(2a-x)^2[2a-(2a-x)]
=1/4ax(2a-x)^2
6.4xy-(x^2+4y^2)
=-(x^2-4xy+4y^2)
=-(x-2y)^2
7.-1/4 (2a-b)^2 +4(a-1/2 b)^2
=2^2(a-1/2 b)^2-(1/2)^2(2a-b)^2
=(2a-b)^2-(a-1/2 b)^2
=(3a-3/2b)(a-1/2b)
1年前
3