5(m-2n)方-3(m+n)+2(m+n)-8(m-2n)方,其中m=-10,n=-6时,怎么算
问题描述:
5(m-2n)方-3(m+n)+2(m+n)-8(m-2n)方,其中m=-10,n=-6时,怎么算
答
(5-8)(m-2n)²-(3-2)(m+n)
=-3(m-2n)²-(m+n)
=-3(-10-2(-6))²-(-10-6)
=-3×2²+16
=-12+16
=4