解方程 2 7 x= 8 21 x÷ 2 5 =15   1 4 x+ 1

解方程 2 7 x= 8 21 x÷ 2 5 =15   1 4 x+ 1 2 x=6 .
2025-03-20 23:44:53
推荐回答(1个)
回答1:

(1)
2
7
x=
8
21

2
7
2
7
=
8
21
÷
2
7

x=
4
3


(2)x÷
2
5
=15,
2
5
×
2
5
=15×
2
5

x=6;

(3)
1
4
x+
1
2
x=6,
x(
1
4
+
1
2
)=6,
3
4
x=6,
3
4
3
4
=6÷
3
4

x=8.