Can someone please help me out with this question??

For this case we have that the variable "s" represents the quantity of slices for each pizza.
In total, 9 pizzas were purchased and 72 slices were obtained. Then we can raise the following equation:
[tex]9s = 72[/tex]
To know the amount of slices of each pizza we clear "s":
[tex]s = \frac {72} {9} = 8[/tex]
Answer:
[tex]9s = 72\\s = 8[/tex]