4x-3(x-3)=5x+3(a+6)
4x-3x+9=5x+3a+18;
4x=-3a-9;
x=(-3a-9)/4;
(1)3a+9＞0;
a＞-3;
(2)(-3a-9)/4＜1/2;
-3a-9＜2;
a＞-11/3;
(3)(-3a-9)/4≤-a;
-3a-9≤-4a;
a≤9;