答案:
(1)1-[1-(+÷)]×,
=1-[1-(+)]×,
=1-[1-1]×,
=1-0×,
=1-0,
=1;
(2)÷[-(+)],
=÷[-],
=÷,
=;
(3)[5.7-4.8×(480%-3.8)]÷0.45,
=[5.7-4.8×1]÷0.45,
=[5.7-4.8]÷0.45,
=0.9÷0.45,
=2;
(4)+4÷,
=987×(654+1)-321 |
666+987×654 |
+4÷,
=987×654+987-321 |
666+987×654 |
+4÷,
=+4÷,
=1+4÷,
=1+18,
=19;
(5)+++…+,
=,
=,
=,
=;
(6)(1++3+9)÷(1+3+9),
=[(1+3+9)+(++)]÷[(1+3+9)+(++),
=[13+]÷[13+],
=[13×(1+)]÷[13×(1+)],
=(1+)÷(1+),
=÷,
=.