Step-by-step explanation:
-81





Answer:
subtract 2 and add 3
Step-by-step explanation:
8-2=6
6+3=9
9-2=7
7+3=10
Answer:
+15
-721
0
+462
-1200
The positives are because it said 'above sea level', the negatives because it said 'below sea level' and zero because it said 'sea level'.
When lines are perpendicular it’s called parallel, it’s when the lines never touch