Answer: 2
Reason:
The 5's cancel out leaving the 2 behind as the final answer.
Another way to look at it is that the 5*2 up top multiplies to 10, then we divide that by the 5 in the denominator to end up with 10/5 = 2
If you are a visual learner, then draw a circle and divide it into 5 equal slices. Do this a total of five times. Each pizza having 2 slices, and 5 pizzas total, gives 2*5 = 10 slices overall. These ten slices can be rearranged into making 2 full pizzas.
See below.