桅杆
幼苗
共回答了20个问题采纳率:85% 举报
设横线上的数字是x,
1÷[(6-2.8)×x]=0.125,
1÷3.2x=0.125,
1÷3.2x×3.2x=0.125×3.2x,
1=0.4x,
1÷0.4=0.4x÷0.4,
x=2.5;
(2)1÷(
4
5 ×x-
1
5 )=3,
1÷(
4
5 x -
1
5 )×(
4
5 x -
1
5 )=3×(
4
5 x -
1
5 ),
1=
12
5 x-
3
5 ,
1+
3
5 =
12
5 x-
3
5 +
3
5 ,
8
5 =
12
5 x,
8
5 ÷
12
5 =
12
5 x ÷
12
5 ,
x=
2
3 .
故答案为:2.5,
2
3 .
1年前
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