Explanation:
f(x) = |x - 3| - 6
This is an absolute value function where there is a sharp inflection point at x = 3. The lowest point of the graph must be -6.
When f(x) = 0, |x - 3| - 6 = 0.
=> |x - 3| = 6, x - 3 = 6 or x - 3 = -6
=> x = 9 or x = -3
Hence the graph crosses the x-axis at x = -3,9.
The answer is the last option.