(1)(1+
1
2 )÷(1-
1
2 ),
=
3
2 ÷
1
2 ,
=3;
答:商是3;
(2)设这个数是x,由题意得:
2
3 x=30×2
1
3 -4,
2
3 x=70-4,
2
3 x=66,
2
3 x ÷
2
3 =66 ÷
2
3 ,
x=99;
答:这个数是99.
(1)(1+
1
2 )÷(1-
1
2 ),
=
3
2 ÷
1
2 ,
=3;
答:商是3;
(2)设这个数是x,由题意得:
2
3 x=30×2
1
3 -4,
2
3 x=70-4,
2
3 x=66,
2
3 x ÷
2
3 =66 ÷
2
3 ,
x=99;
答:这个数是99.