(m+3)(-m-3)等于( ) A.-m2-6m-9 B.-m2+6m+9 C.m2-6m+9 D.-m2+6m-9
问题描述:
(m+3)(-m-3)等于( )
A. -m2-6m-9
B. -m2+6m+9
C. m2-6m+9
D. -m2+6m-9
答
原式=-(m+3)2=-m2-6m-9.
故选A