(m+2n)(2m+4n-5)+2,用十字相乘法
问题描述:
(m+2n)(2m+4n-5)+2,用十字相乘法
答
(m+2n)(2m+4n-5)+2
=2(m+2n)²-5(m+2n)+2
=[2(m+2n)-1][(m+2n)-2]
=(2m+4n-1)(m+2n-2)
如仍有疑惑,欢迎追问.祝: