|m+4|与n^2-2n+1互为相反数,
|m+4|+n^2-2n+1=0
|m+4|+(n-1)²=0
所以m+4=0 n-1=0
m= -4 n=1
(x^2+4y^2)-(mxy+n)
=(x²+4y²)-(-4xy+1)
=x²+4xy+4y²-1
=(x+2y)²-1
=(x+2y+1)(x+2y-1)
|m+4|与n^2-2n+1互为相反数,
|m+4|+n^2-2n+1=0
|m+4|+(n-1)²=0
所以m+4=0 n-1=0
m= -4 n=1
(x^2+4y^2)-(mxy+n)
=(x²+4y²)-(-4xy+1)
=x²+4xy+4y²-1
=(x+2y)²-1
=(x+2y+1)(x+2y-1)