 
 <prompt> Ni igbekele ti o ni awon omo ile iwosan, won ni 4 pizas ti won se eebun si 12 ni gbogbo eebun kan. Ti awon omo ile iwosan ba je 39 ni gbogbo eebun, ni ojojumo ni gbogbo eebun ti won se je? <response>: There’s a total of 4 x 12 = 48 slices.
After the guests eat, there are 48 - 39 = 9 pieces.

Answer is 9. 