1.如圖所示,數(shù)軸上從左到右的三個(gè)點(diǎn)A,B,C所對(duì)應(yīng)數(shù)的分別為a,b,c.其中點(diǎn)A、點(diǎn)B兩點(diǎn)間的距離AB的長(zhǎng)是20,點(diǎn)B、點(diǎn)C兩點(diǎn)間的距離BC的長(zhǎng)是8.
(1)若以點(diǎn)C為原點(diǎn),直接寫出點(diǎn)A,B所對(duì)應(yīng)的數(shù);
(2)若原點(diǎn)O在A,B兩點(diǎn)之間,求|a|+|b|+|b-c|的值;
(3)若O是原點(diǎn),且點(diǎn)B到原點(diǎn)O的距離是6,求a+b-c的值.