一、计算下面各题

90×12－800          252÷4＋37           86×25＋1850

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468÷6＋278         145×28＋107         905×32－1800

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200－15×8           200＋16×7            200－150÷5

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900＋105×8          3250－595÷7          396－25×6

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（200－15）×8     （ 200＋16）×7      （200－150）÷5

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（900＋105）×8   （3250－1150）÷7     （396－36）×6

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90×（12－8 ）     405÷（4＋5）         86×（25＋1850）

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468÷（569－563）    145×（28＋107）    905×（32－18）

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85＋125＋508       7805－85－627    824＋631－31

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285－25＋508       6205÷5×36      24×31×56

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441÷7÷9          82×14÷4        824÷2×6

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