7x+6=8-3x
7x+3x=8-6.
10x=2,
x=2/10.
x=1/5
6-3(x+2/3)=2/3,
6-3x-2=2/3.
3x=4-2/3,
=10/3.
x=10/9.
4x-3(20-x)=6x-7(9-x).
4x-3x-3*20=6x-7*9+7x.
13x-x=63-60.
12x=3,
x=1/4.
2x+1/3-5x-1/6=1.
-3x=1-1/3+1/6.
=5/6.
x=-5/18