Answer:
7 pizzas
Step-by-step explanation:
You just minus 72 from 9 and once you get to 9 dollars you still have enough to time the delivery guy and you would have 4 dollars left.
-x+4>-3x-4
+x +x
---------------------
4>-3x-4
+4 +4
----------------
8>-3x
/3 /3
----------------
8>2.7
x=2.7
Hope it helped!