题目内容
【题目】解方程
(1)28.25﹣X=8.25,
(2)X﹣(3.6+2.97)=12.42,
(3)x+30%x=26,
(4)÷x=,
(5)14.5=5.5,
(6)x﹣80%x=48,
(7)75%x﹣5×=6,
【答案】x=20 x=18.99 x=20 x= x=160 x=240 x=12
【解析】
(1)28.25﹣X=8.25,
解:28.25﹣X+X=8.25+X,
X+8.25=28.25,
X+8.25﹣8.25=28.25﹣8.25,
X=20;
(2)X﹣(3.6+2.97)=12.42,
解:X﹣6.57=12.42,
X﹣6.57+6.57=12.42+6.57,
X=18.99
(3)x+30%x=26
解:130%x=26
1.3x=26
1.3x÷1.3=26÷1.3
x=20
(4)÷x=,
解:÷x×x=×x,
x=,
x÷=÷,
x=×,
x=;
(5)14.5=5.5,
解:14.5+14.5=5.5+14.5,
=20,
×8=20×8,
x=160
(6)x﹣80%x=48,
解:(1﹣0.8)x=48,
0.2x=48,
0.2x÷0.2=48÷0.2,
x=240;
(7)75%x﹣5×=6,
解:0.75x﹣3=6,
0.75x﹣3+3=6+3,
0.75x=9,
0.75x÷0.75=9÷0.75,
x=12
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