Answer is a. (-13, 12) b. (4, 11)
Step by step
When your rule is
(x,y) ➡️ (x -8, y +2)
a)
You take your input (-5, 10) and add your input rule to that input to get your output.
Input of x is -5, add x rule -8 = -13
Input of y is 10, add y rule +2 = 12
Your output or new coordinate is (-13, 12)
b) You take your input (12, 9) and add your input rule to that input to get your output.
Input of x is 12, add x rule -8 = 4
Input of y is 9, add y rule +2 = 11
Your output or new coordinate is ( 4, 11)
If your rule changes the process is still the same. Remember to watch adding or subtracting negatives. You can use a graph and plot your input and count out your “rule” to double check your work if you want.