题目内容
【题目】3÷〔9×( )〕×12
93.6÷〔(6﹣2.88)×( ﹣1.875)〕
7.05×37+64×7.05﹣7.05
÷〔7.8+ ×(2.75+1.25)〕
8.1÷( )÷ .
【答案】解:①3÷[9×( )]×12,
=3÷[9× ×9]×12,
=3÷[ ﹣ ]×12,
=3 ×12,
=36×12,
=432;
②93.6÷[(6﹣2.88)×( ﹣1.875)],
=93.6÷[3.12×4],
=93.6÷12.48,
=7.5;
③7.05×37+64×7.05﹣7.05,
=7.05×(37+64﹣1),
=7.05×100,
=705;
④ ,
=( ×0.8+ ×6.2﹣5.8× ﹣ ×0.2)× ,
=[ ×(0.8+6.2﹣5.8﹣0.2)]× ,
=[ ×1]× ,
= × ,
=1;
⑤ ÷[7.8+ ×(2.75+1.25)],
= ÷[7.8+ ×4],
= ÷(7.8+1),
=8.8÷8.8,
=1;
⑥8.1÷( )÷ ,
=8.1÷(4 ﹣3.5)÷ ,
= ,
= ,
=
【解析】(1)先把中括号里面的运用乘法分配律简算,再把括号外的按照从左到右的顺序计算;(2)先同时运算小括号里面的减法,再算中括号里面的乘法,最后算括号外的除法;(3)运用乘法分配律简算;(4)先把小括号里面的运用乘法分配律简算,再算括号外的乘法;(5)先算小括号里面的加法,再算中括号里面的乘法,然后算中括号里面的加法,最后算括号外的除法;(6)先算小括号里面的乘法,再算小括号里面的减法,再算括号外的除法.
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