问题 解答题
解方程
(1)2x-1
13
20
+2.35=9
(2)x:
7
10
=0.3x+12.
答案

(1)2x-1

13
20
+2.35=9,

2x+0.7=9,

2x+0.7-0.7=9-0.7,

2x=8.3,

2x÷2=8.3÷2,

x=4.15;

(2)x:

7
10
=0.3x+12.

10
7
=0.3x+12,

10
7
x=
3
10
x+12,

100
70
x-
21
70
x=
21
70
x-
21
70
x+12,

79
70
x=12,

79
70
70
79
=12×
70
79

x=

840
79

x=10

50
79

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