1-（1-30%）x（1+20%）的等式计算的过程

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1-（1-30%）x（1+20%）
=1-70%x120%
=1-84%
=16%

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1-（1-30%）×（1+20%）
=1-0.7×1.2
=1-0.84
=0.16

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=1-0.7×1.2
=1-0.84
=0.16

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