(x减0.8)除以3.1等于4

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(x-0.8)÷3.1=4
x-0.8=3.1*4
x-0.8=12.4
x=13.2

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解逗慧：(x-0.8)/3.1=4
去分母悔旦，得：x-0.8=12.4
两边同时加上0.8，得碧指扰：x=13.2

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13.2

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