Expand the parentheses:
-6+3x<2x-9
Add 6 to each side:
3x<2x-3
Subtract 2x from each side:
x<-3
So any value of x less than -3 is a solution. For example, x=-4 in the original gives us:
-3(2-(-4))<-8-9, -3×6<-17, -18<-17 which is true, because -18 is less than (more negative than) -17.
We would not expect x=0 to be a solution, so if we put x=0 in the original we would expect it to be false:
-3(2)<-9, -6<-9 is false because -6 is greater than (more positive than) -9.