9.75-15÷19-19/2×2能簡算嗎?

9.75-15÷19-19/2×2能簡算嗎?


=9.75-19/15-19/4
=9.75-(19/15+19/4)
=9.75-1
=8.75



[2.25+0.75×(5/12×0.15)]×5/12簡算
怎麼算?


[2.25+0.75×(5/12×0.15)]×5/12
=[9/4+3/4(5/12×3/20)]×5/12
=3/4×(3+1/16)×5/12
=3/4×49/16×5/12
=(49×5)/(16×16)
=245/256



1+2+2+3+3+3+6+9+9+6+5+78+45+46+4+45+6+4+5+45+465+5+4+6+45+4+7+5=?


868



0.45乘1.8豎式怎.麼列


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