问题 解答题
解方程.
X-
7
9
=
7
9
5
7
+X=
3
2
5X=7X÷0.5=0.78.
答案

(1)x-

7
9
=
7
9

x-

7
9
+
7
9
=
7
9
+
7
9

x=1

5
9

(2)

5
7
+x=
3
2

5
7
+x-
5
7
=
3
2
-
5
7

x=

11
14

(3)5x=7,

5x÷5=7÷5,

x=1.4;

(4)x÷0.5=0.78,

x÷0.5×0.5=0.78×0.5,

x=0.39.

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