问题 解答题
解方程.
(1)3x+3×6
1
2
=31.2;
(2)7x-3
2
5
x=0.72.
答案

(1)3x+3×6

1
2
=31.2,

3x+19.5=31.2,

3x+19.5-19.5=31.2-19.5,

3x=11.7,

3x÷3=11.7÷3,

x=3.9;

(2)7x-3

2
5
x=0.72,

(7-3.4)x=0.72,

3.6x=0.72,

3.6x÷3.6=0.72÷3.6,

x=0.2.

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