问题 解答题
解方程.
x+0.75-
3
5
=0.15
2x+
5
8
=4.625
4
5
-2X=
1
4

2.7X-1.6=38.9.
答案

(1)x+0.75-

3
5
=0.15,

x+0.15=0.15,

x+0.15-0.15=0.15-0.15,

x=0,

(2)2x+

5
8
=4.625,

2x+

5
8
-
5
8
=4.625-
5
8

2x=4,

x=2,

(3)

4
5
-2X=
1
4

4
5
-2x+2x-
1
4
=
1
4
+2x-
1
4

11
20
=2x,

2x=

11
20

x=

11
40

(4)2.7x-1.6=38.9,

2.7x-1.6+1.6=38.9+1.6,

2.7x=40.5,

2.7x÷2.7=40.5÷2.7,

x=15.

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