9.6-5x+8x=30
3x=20.4
x=6.8
2(1.2+0.5x)=4x
2.4+x=4x
-3x=-2.4
x=0.8
1.2(x-5)+1.5=1.62
1.2(x-5)=0.12
x-5=0.1
x=5.1
120+x=7(x-12)
120+x=7x-84
x-7x=-84-120
-6x=-204
x=34