Hi, there--

You can solve this problem by working backwards, undoing both transformations by doing 
the opposite.

Start with y=|3x-9|

The second transformation was "1 unit up." We'll translate our equation "1 unit down." 
Subtracting 1 outside the absolute value sign will translate the graph 1 unit down.
y = |3x-9| -1

The first transformation was "2 units to the left." We can undo this one by translating "2 
units to the right." Subtracting 2 from x translates a function 2 units to the right.
y = |3(x-2)-9| - 1

Now we are back at the original function. We can leave it this way, but typically we would 
simplify the expression inside the absolute value symbols.
y = |3x-6-9| - 1
y = |3x-15|-1

There you go!
Mrs. Figgy