第1个回答 2019-12-07
解:(1)4-23x=25,
4-23x+23x-25=25+23x-25,
185=23x,
23x=185,
23x×32=185×32,
x=275,
(2)x:34=13,
x:34=1:3,
3x=1×34,
3x÷3=34÷3,
x=14,
(3)2x+0.7=7.7,
2x+0.7-0.7=7.7-0.7,
2x=7,
2x÷2=7÷2,
x=3.5,
(4)x-25%x=0.5.
0.75x=0.5,
0.75x÷0.75=0.5÷0.75,
x=23.