HU NAN DA XUE JING PIN KE CHENG 证 (1)AB= 222 O 1)(0 (2)AC= 1-1八(13 2-5 000000 AD= 33 故AC=AD AO 高等粤证：       − −       − − = 2 1 2 1 1 1 1 1 (1) AB       = 0 0 0 0 = O       −       − − = 1 3 2 3 1 1 1 1 (2) AC       − = 3 0 3 0       −       − − = 2 5 2 5 1 1 1 1 AD       − = 3 0 3 0 故 AC ＝ AD