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脱式计算.20-[7.8+(6.2+1.29)];9.4×[1.28-(1.54-0.31)];15.4÷[8×(6.34-4.59)];9.83×1.5+6.17×1.5+27.8.

题目详情
脱式计算.
20-[7.8+(6.2+1.29)];
9.4×[1.28-(1.54-0.31)];
15.4÷[8×(6.34-4.59)];
9.83×1.5+6.17×1.5+27.8.
▼优质解答
答案和解析
(1)20-[7.8+(6.2+1.29)]
=20-[7.8+7.49]
=20-15.29
=4.71;

(2)9.4×[1.28-(1.54-0.31)]
=9.4×[1.28-1.23]
=9.4×0.05
=0.47;

(3)15.4÷[8×(6.34-4.59)]
=15.4÷[8×1.75]
=15.4÷14
=1.1;

(4)9.83×1.5+6.17×1.5+27.8
=1.5×(9.83+6.17)+27.8
=1.5×16+27.8
=24+27.8
=51.8.