Answer:
3p=12
Explanation:
Each friend has 3 slices of pizza so the total number of slices of pizza is equal to 3+3+...+3 (p times). This sum is equal to 3p. In total, there are 12 slices of pizza then 12=3p.
You can also find out the number of friends. Dividing by 3 in both sides of the previous equation, 4=p so there are 4 friends. To verify this, assume that there are 4 friends and 12 slices of pizza. The number of slices that each friend must to be equally divided is 12/4=3 (numerator= number of slices) (denominator=number of people you will divide the pizza).