zengzh118
春芽
共回答了13个问题采纳率:100% 举报
1.m-n=0,m=n
m^3-n^3-3mn
=-3m^2
2.x^2-2x+y^2+6y+10=0
=(x-1)^2+(y+3)^2=0
要使等式成立
x-1=0,y+3=0
x=1,y=-3
x+y=-2
3.w^1980+w^1981+...+w^2000
=w^1980(1+w^1+w^2+...w^20)
=w^1980[(1+w+w^2)+w^3(1+w+w^2)+.w^18(1+w+w^2)]
=w^1980(0+0+.0+
=0
4.m^2+m-2=0
(m+2)(m-1)=0
m=-2或者m=1
所以
m=1时
m^3+3m^2+2001=2005
m=-2时
m^3+3m^2+2001=2005
1年前
1