0.3(x+4)=120 (x-25)÷6=7 8(x-12)=144 (x+9)÷3=13 12x-12=0 0.5(

1、0.3(x+4)=120
x+4=400
x=396
2、(x-25)÷6=7
x-25=42
x=67
3、8(x-12)=144
x-12=18
x=30
4、(x+9)÷3=13
x+9=39
x=30
5、12x-12=0
12x=12
x=1
6、0.5(2x+4)=4.2
2x+4=8.4
2x=4.4
x=2.2