问题 解答题
解方程.
370+x=480
0.7x=0.91x-8.3=16.4
x÷12=180x+
2
7
=
5
7
8.6-x=2.8.
答案

(1)370+x=480,

370-370+x=480-370,

x=110;

(2)0.7x=0.91,

0.7x÷0.7=0.91÷0.7,

x=1.3;

(3)x-8.3=16.4,

x-8.3+8.3=16.4+8.3,

x=24.7;

(4)x÷12=180,

x÷12×12=180×12,

x=2160;

(5)x+

2
7
=
5
7

x+

2
7
-
2
7
=
5
7
-
2
7

x=

3
7

(6)8.6-x=2.8,

8.6-x+x=2.8+x,

2.8+x=8.6,

2.8-2.8+x=8.6-2.8,

x=5.8.

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