1)9,888-1/18-7,888=2-1/18=1 17/18

2)3 1/3:2,4=1 7/18

3)1 7/18+1 17/18=3 1/3 

3 1//3:2,4+9,888-(1//18+7,888)=25//18+9.888-(1//18+7.888)=25373//2250-17873//2250=10//3=3 1/3 

// - черта дроби