We need to find the horizontal shift of the absolute value function given by:
f(x) = 3 |x+6| + 9
So we recall that all horizontal shifts are associated with additions and subtractions to strictly the x-valriable.
So in our case what is affecting the x variable with additions or subtractions is in fact the x+6 (addition of 6 units to the x-variable).
Such type of transformation produces a shift to the left in 6 units.
So it is the x+6 what causes a horizontal shift in the graph of the function of 6 units to the left.