甲数与乙数的比是7:9,乙数是甲数的________,甲数是甲、乙两数之和的________.
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分析:甲数与乙数的比是7:9,把甲数看成7份,那么乙数就是9份;用乙数除以甲数,就是乙数是甲数的几分之几;求出两数的和,用甲数除以两数的和,就是甲数是两数和的几分之几.
解答:甲数与乙数的比是7:9,把甲数看成7份,那么乙数就是9份;
9÷7=
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;
7÷(9+7)=
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;
答:乙数是甲数的
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,甲数是甲、乙两数之和的
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.
故答案为:
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,
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.
点评:本题根据比的关系设出数据,再根据求一个数是另一个数几分之几的方法求解.