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(1)7.8×9.8-14.5,=76.44-14.5,=61.94;(2)13.4+

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/21 08:52:29
(1)7.8×9.8-14.5,
=76.44-14.5,
=61.94;

(2)13.4+5.62+17.6+4.38,
=(13.4+17.6)+(5.62+4.38),
=31+10,
=41;

(3)3.6×42+4.2×64,
=36×4.2+4.2×64,
=4.2×(36+64),
=4.2×100,
=420;

(4)4.8×12.5×0.8,
=4.8×(12.5×0.8),
=4.8×10,
=48;

(5)1.76-[(0.74+0.26)÷0.8],
=1.76-[1÷0.8],
=1.76-1.25,
=0.51;

(6)(1.89+1.4×3)÷0.25,
=(1.89+4.2)÷0.25,
=6.09÷0.25,
=24.36.