(m+n)²-6n-6m+9=
问题描述:
(m+n)²-6n-6m+9=
答
(m+n)²-6n-6m+9
=(m+n)²-6(n+m)+9
= (m+n-3)²
(m+n)²-6n-6m+9=
(m+n)²-6n-6m+9
=(m+n)²-6(n+m)+9
= (m+n-3)²