1) To find that the corresponding points, let'-s plug it into that formula:
(2, -6)
If we plug 2 and we have output the number -6, then f(x) is y= -3x
-2f(x+3) is the function f(x) with a horizontal shift of 3 units to left, a vertical stretch, a reflection.
2) y=-2(2+3) then y=-2(5) y=-10
So point (2,-6) will correspond to (2,-10)