Question

解方程 求 跪帮忙解一下

x/2=3x-1
1/2(x-3)=2- 1/2(x-3)
(3y+12)/4=2-(5y-7)/3
(0.1x-0.2)/0.02-(x+1)/0.5=3

Answer 1

x/2=3x-1
同时乘以2，得
x=6x-2
5x=2
x=2/5

1/2(x-3)=2-1/2(x-3)
同时乘以2，得
x-3=4-(x-3)
x-3=4-x+3
x-3=7-x
2x=10
x=5

(3y+12)/4=2-(5y-7)/3
同时乘以12，得
3(3y+12)=24-4(5y-7)
9y+36=24-20y+28
9y+36=52-20y
29y=16
y=16/29

(0.1x-0.2)/0.02-(x+1)/0.5=3
同时乘以100，得
50(0.1x-0.2)-2(x+1)=3
5x-10-2x-2=3
3x=15
x=5