（1）6+2（x-3)=X
6+2x-6=x
2x-x=0
x=0
(2)8-2(x-7)=x-(x-4)
8-2x+14=x-x+4
-2x=-18
x=9
(3)2x-(1.5x-1)=2(1.5x-1)
2x-3(1.5x-1)=0
2x-4.5x=-3
-2.5x=-3
x=6/5