A
分析:直接利用向量加減法混合運(yùn)算的性質(zhì),我們可以逐一的對(duì)四個(gè)結(jié)論進(jìn)行判斷,易得答案.
解答:因?yàn)?img class='latex' src='http://thumb.1010pic.com/pic5/latex/13080.png' />=2
-
≠
,故A錯(cuò),
因?yàn)?img class='latex' src='http://thumb.1010pic.com/pic5/latex/13084.png' />-
=
+
=
=
,故B對(duì);
因?yàn)?img class='latex' src='http://thumb.1010pic.com/pic5/latex/13088.png' />=
=
,故C對(duì);
因?yàn)?img class='latex' src='http://thumb.1010pic.com/pic5/latex/13090.png' />+
=
+(
)=
,故D對(duì).
故選A.
點(diǎn)評(píng):本題考查向量加減法混合運(yùn)算的性質(zhì).是對(duì)課本基礎(chǔ)知識(shí)的考查,是基礎(chǔ)題.