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用递等式计算.①4.87-0.74+0.13-0.26②0.1×[1÷(2.7-2.66)+0.5]③14.75÷4÷0.25④(1.25×0.8÷1.25x0.8)÷20⑤(8.4+8.4+8.4+8.4)×2.5-0.1⑥14.2×6.3+27×1.42+0.142÷0.01.

题目详情
用递等式计算.
①4.87-0.74+0.13-0.26 ②0.1×[1÷(2.7-2.66)+0.5]
③14.75÷4÷0.25 ④(1.25×0.8÷1.25x0.8)÷20
⑤(8.4+8.4+8.4+8.4)×2.5-0.1 ⑥14.2×6.3+27×1.42+0.142÷0.01.
▼优质解答
答案和解析
①4.87-0.74+0.13-0.26,
=(4.87+0.13)-(0.74+0.26),
=5-1,
=4;

②0.1×[1÷(2.7-2.66)+0.5],
=0.1×[1÷0.04+0.5],
=0.1×(25+0.5),
=0.1×25.5,
=2.55;

③14.75÷4÷0.25,
=14.75÷(4×0.25),
=14.75÷1,
=14.75;

④(1.25×0.8÷1.25×0.8)÷20,
=(1÷1.25×0.8)÷20,
=(0.8×0.8)÷20,
=0.64÷20,
=0.032;

⑤(8.4+8.4+8.4+8.4)×2.5-0.1,
=(8.4×4)×0.25-0.1,
=8.4×(4×0.25)-0.1,
=8.4×1-0.1,
=8.4-0.1,
=8.3;

⑥14.2×6.3+27×1.42+0.142÷0.01,
=14.2×6.3+2.7×1.42+14.2×1,
=14.2×(6.3+2.7+1),
=14.2×10,
=142.