Answer:

Step-by-step explanation:

9. 31 + 5 = 36
10. 16 - 4 = 12
12. 9
13. 44 + 34 = 78
14. 101 - 1 = 100
15. -539 ???
16. 15 ??
17. |-435| = 435
The midpoint of AC is (-1.5, 20)
1/5 of a foot
Simply subtract the height of Pancho’s sandcastle (3/5 of a foot) minus the height of his sister’s sandcastle (2/5 of a foot) to find a difference of 1/5 of a foot, meaning Pancho’s sandcastle was 1/5 of a foot taller than his sister’s sandcastle.