(1) 5 8 ×15+ 5 8 =(15+1)× 5 8 ,=16× 5 8 ,=10;(2)2? 6 13 ÷ 9 26 ? 2 3 =2- 6 13 × 26 9 - 2 3 ,=2-1 1 3 - 2 3 ,=2-(1 1 3 + 2 3 ),=2-2,=0;(3)( 1 2 + 1 3 ? 1 4 )×12= 1 2 ×12+ 1 3 ×12- 1 4 ×12,=6+4-3,=7.