Please help me thx here is the pic below

Look below

Step-by-step explanation:

For number 7:  The answer is reasonable because 20-2.3=17.7

To prove this, you can add 17.7 to 2.3 and get 20 or you can subtract 20 from 17.7 to get 2.3.

20-17.7=2.3

17.7+2.3=20

For number 8: 10.65

To prove this just add 1.32 to 9.33

9.33+1.32=10.65

For number 9: 4.32

To prove this just subtract 13.65 (3rd place runner) from 9.33 (second place runner)

13.65-9.33=4.32

For Number 10: 14.13

To prove this, just subtract 61.05 (Miami) form  46.92 (Albany)

61.05-46.92=14.13

For Number 11: To subtract 7.6 from 20.39 all you do is this.

First set your numbers up like this

20.39

-    7.6

Then you would do as you would do with normal subtraction.

9-6=3

because you cant subtract 7 from 3 you borrow 10 from 0. But because you cant do that you have to borrow it from 2. So now you have 13-7 which is 6. Also the 0 is now a 9 and the 2 is a 1.

Then you just drop the 1 and the 9 and you should get 19.63.

I know math can be confusing sometimes so hopefully this helped.