问题 解答题

计算下面各题(能简算的要简算)

48-2.3×12

50×(0.8+0.4)

7.34×2.1+7.34×7.8+7.34×1.1

20.5÷1.25÷0.8

(8.1-5.4)÷3.6+85.7

9.88×9+9.88.

答案

①48-2.3×12,

=48-27.6,

=20.4;

②50×(0.8+0.4),

=50×0.8+50×0.4,

=40+20,

=60;

③7.34×2.1+7.34×7.8+7.34×1.1,

=7.34×(2.1+7.8+1.1),

=7.34×10,

=73.4;

④20.5÷1.25÷0.8,

=20.5÷(1.25×0.8),

=20.5÷1,

=20.5;

⑤(8.1-5.4)÷3.6+85.7,

=2.7÷3.6+85.7,

=0.75+85.7,

=86.45;

⑥9.88×9+9.88,

=9.88×(9+1),

=9.88×10,

=98.8.

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