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25/67x68=25/67x(67+1)=25/67x67+25/67=25+25/67=25又25/67
67分之25×68 =67分之25×(67+1) =67分之25×67+67分之25×1 =25+67分之25 =25又67分之25
33×1/11×5/7×1/5
25/67*68=1700/67