Answer:
(7, 8)
Step-by-step explanation:
If Sidney places each piece 3 units east and 2 units north of the last one, we can figure out which coordinate comes first by subtracting the position of the second piece (S) by the position of the first piece (F):

We can conclude that coordinates are in the (East, North) format.
Therefore, the location of the third piece (T) is:

Answer:
Place both coordinates for the first question on a graph and draw a line. The answer is the coordinate that falls on that line.
Step-by-step explanation:
Answer: Y2-Y1 over X2-X1 which gives you 7/-11
Step-by-step explanation:
15. -2
16. A. The pool was originally empty