1.若m*m+n*n-6n+4m+13=0,则m*m-n*n为____________
1个回答

(平方²按住ALT打178,立方³按住ALT打179)

M²+N²-6N+4M+13=0

(M²+4M)+(N²-6N)=-13

(M²+4M+4)+(N²-6N+9)=-13+4+9

(M+2)²+(N-3)²=0

(M+2)²=0,M=-2

(N-3)²=0,N=3

M²-N²=4-9=-5

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2)

M²+M-1=0,,M²+M=1

M³+2M²+2004=M³+M²+M²+2004=M(M²+M)+M²+2004=M²+M+2004=1+2004=2005