We ordered 7 pizzas. Each pizza has the same number of slices. If there were a total of 14 slices how many slices are there in each pizza?
There are 7 pizzas. So, we have 7x slices in total. 
Each pizza has the same number of slices, so we can write: 
7x=y⋅7
y is the number of slices in each pizza. 
We know that there are 14 slices in total. So: 
7x=14
y=2

There are 2 slices in each pizza.