(++)×237-0.37×8.28-3.7×0.172(2-1)×1.6÷(1.82×)[6-(+)×30]÷(1×0.9)[0.75-(2-1)÷4]÷[(1+2

发布时间:2020-07-30 23:53:38

(++)×2
37-0.37×8.28-3.7×0.172
(2-1)×1.6÷(1.82×)
[6-(+)×30]÷(1×0.9)
[0.75-(2-1)÷4]÷[(1+2)÷2-].

网友回答

解:(1)(++)×2,
=×+×+×,
=×+×+,
=(++)×,
=(++)×,
=×,
=;

(2)37-0.37×8.28-3.7×0.172,
=3.7×10-3.7×0.828-3.7×0.172,
=(10-0.828-0.172)×3.7,
=[10-(0.828+0.172)]×3.7,
=[10-1]×3.7,
=10×3.7-3.7,
=37-3.7,
=33.3;

(3)(2-1)×1.6÷(1.82×),
=()×÷,
=××,
=;

(4)[6-(+)×30]÷(1×0.9),
=[6-()×30]÷(),
=[6-30]÷,
=[6-]×,
=×,
=;

(5)[0.75-(2-1)÷4]÷[(1+2)÷2-],
=[-()×]÷[(1+2)÷-],
═[-×]÷[×-],
=[-]÷[-],
=÷,
=,
=.

解析分析:(1)运用乘法分配律计算,但要注意把结果写成×+×+,然后再运用乘法分配律的逆运算简算;(2)根据积不变的规律,把原式改写成3.7×10-3.7×0.828-3.7×0.172,然后运用乘法分配律的逆运算简算;(3)把小数化为分数,然后按运算顺序计算,先算括号内的,再算括号外的;(4)把小数改为分数,然后按运算顺序计算,用乘法分配律计算(+)×30;(5)此题含有两个中括号,同时进行计算,两部分都是先算小括号内的,再算中括号内的.

点评:此题考查学生对四则混合运算顺序的掌握情况,以及对运算定律的恰当使用.
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