问题 解答题
解下列方程
3
4
+
1
4
X﹦
7
8
X+10%﹦1
1
2
X-
3
4
×
8
9
﹦1
1
3
5
12
X-5﹦30.
答案

(1)

3
4
+
1
4
x=
7
8

3
4
+
1
4
x-
3
4
=
7
8
-
3
4

1
4
x=
1
8

1
4
1
4
=
1
8
÷
1
4

x=

1
2

(2)X+10%﹦1,

X+10%-10%﹦1-10%,

x=0.9;

(3)

1
2
X-
3
4
×
8
9
﹦1
1
3

1
2
X-
2
3
+
2
3
﹦1
1
3
+
2
3

1
2
x=2,

1
2
1
2
=2÷
1
2

x=4;

(4)

5
12
X-5=30,

5
12
X-5+5=30+5,

5
12
X=35,

5
12
5
12
=35÷
5
12

x=84.

综合
单项选择题