问题 解答题

(1)2x+2.7=24.7

(2)x-0.2x=5.6

(3)2.5:5=
1
2
:x.
答案

(1)2x+2.7=24.7

2x+2.7-2.7=24.7-2.7,

2x=22,

2x÷2=22÷2,

x=11;

(2)x-0.2x=5.6

x(1-0.2)=5.6,

0.8x=5.6,

0.8x÷0.8=5.6÷0.8,

x=7;

(3)2.5:5=

1
2
:x

2.5x=5×

1
2

2.5x÷2.5=

5
2
÷2.5,

x=1.

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