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用你喜欢的方法计算下面各题99×4.2+4.20.25×1.25×3.26.4×14+15×6.4+6.4(1.3+1.3×0.125×8)÷(80-77.4)4×(25+2.5+0.25)÷1116.25÷〔(17.2-3.6×4.5)÷0.32〕

题目详情
用你喜欢的方法计算下面各题
99×4.2+4.2

0.25×1.25×3.2
6.4×14+15×6.4+6.4 (1.3+1.3×0.125×8)÷(80-77.4)
4×(25+2.5+0.25)÷111 6.25÷〔(17.2-3.6×4.5)÷0.32〕
▼优质解答
答案和解析
(1)99×4.2+4.2
=4.2×(99+1),
=4.2×100,
=420;

 (2)0.25×1.25×3.2
=0.25×1.25×(4×0.8),
=0.25×4×(1.25×0.8),
=1×1,
=1;

(3)6.4×14+15×6.4+6.4
=6.4×(14+15+1),
=6.4×30,
=192;

(4)(1.3+1.3×0.125×8)÷(80-77.4)
=(1.3+1.3×1)÷2.6,
=2.6÷2.6,
=1;

(5)4×(25+2.5+0.25)÷111
=(4×25+4×2.5+4×0.25)÷111,
=(100+10+1)÷111,
=111÷111,
=1;

(6)6.25÷[(17.2-3.6×4.5)÷0.32]
=6.25÷[(17.2-16.2)÷0.32],
=6.25÷(1÷0.32),
=6.25÷3.125,
=2.