Let's start by solving each part of the expression separately:

-9 × 2 = -18
4 × (-7.2) = -28.8
-3 × 1.8 = -5.4
3.6

Now, substitute these values back into the expression:

(-18 + (-28.8)) / (-5.4 + 3.6)

Now, simplify the expression:

(-18 - 28.8) / (-1.8)

(-46.8) / (-1.8)

The final answer is 26.