爱ll的猫 幼苗
共回答了23个问题采纳率:95.7% 举报
(1)1-[1/2]×{1-[1/3]×[1-[1/4]×(1-[1/5])]},
=1-[1/2]×{1-[1/3]×[1-[1/4]×[4/5]]},
=1-[1/2]×{1-[1/3]×[1-[1/5]]},
=1-[1/2]×{1-[1/3]×[4/5]},
=1-[1/2]×{1-[4/15]},
=1-[1/2]×[11/15],
=1-[11/30],
=[19/30];
(2)5.6×69.32+138.64×2.2,
=5.6×69.32+(69.32×2)×2.2,
=5.6×69.32+69.32×4.4,
=(5.6+4.4)×69.32,
=10×69.32,
=693.2;
(3)138×1[1/4]+23.3×(2-75%)-125%×38+(1+0.25)×28.7,
=138×1.25+23.3×1.25-1.25×38+1.25×28.7,
=(138+23.3-38+28.7)×1.25,
=[(138-38)+(23.3+28.7)]×1.25,
=[100+52]×1.25,
=152×1.25,
=190.
点评:
本题考点: 整数、分数、小数、百分数四则混合运算.
考点点评: 考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.
1年前
1年前1个回答
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