Question

已知|m+4|+n^2-2n+1=0,把多项式x^2+4y^2-(mxy+n)分解因式

Answer 1

绝对值和平方都应该是大于等于0的,而若他们的和为0

则每一个绝对值或平方项都应为0

m+4=0 m=-4

n^2-2n+1=0 n=1

x^2+4y^2-(-4xy+1)

=x^2+4xy+4y^2-1

=(x+2y)^2-1

=(x+2y+1)(x+2y-1)