Answer:
Explanation:
Total for football: 9 +7
Total for figure skating: 12 +7
NEW Total for football: 16
NEW Total for figure skating: 19
The question says that 9 people like football
The question says that 12 people like to watch figure skating
The question also says that 7 people like to watch both, and because of that, you should add 7 to both 9 and 12, but keep the new numbers separated from each other. So once we know the sum of 9 +7 is 16, and 12 + 7 is 19, we can subtract the two numbers, and get 3 as the answer. Because you are counting the number of times that you have to travel up or down to the other number, and so if you are on a set of stairs that go up to the 16 level and you are on the 14th level, you need to travel up 2 sets of stairs to get to level 16.
Hope that example helps and can help in the future with other problems!