Question

在數(shù)軸上表示，，，四個(gè)數(shù)的點(diǎn)如圖所示，如果為的中點(diǎn).
那么＋＋=        ．

Answer 1

-a

試題分析：由數(shù)軸結(jié)合為的中點(diǎn)可得，且，再根據(jù)絕對(duì)值的規(guī)律化簡(jiǎn).
由數(shù)軸結(jié)合為的中點(diǎn)可得，且
則＋＋
點(diǎn)評(píng)：解答本題的關(guān)鍵是熟記絕對(duì)值的規(guī)律：正數(shù)和0的絕對(duì)值是它本身；負(fù)數(shù)的絕對(duì)值的它的相反數(shù).