问题 解答题
求未知数x.
①x-
1
3
+
2
3
=
3
4

1.2
7.5
=
0.4
x
答案

x-

1
3
+
2
3
=
3
4

x-

1
3
+
2
3
-
2
3
=
3
4
+
2
3

x-

1
3
=
17
12

x=

17
12
+
1
3

x=1

3
4

(2)

1.2
7.5
=
0.4
x

1.2x=0.4×7.5,

1.2x=3,

1.2x÷1.2=3÷1.2

x=2.5.

单项选择题