Answer:
(x+9, y+3)
Explanation:
The graph shows that T(x, y) = (x+3, y+1).
Application of that transform again gives ...
T²(x, y) = T(T(x, y)) = T(x +3, y +1) = ((x +3)+3, (y+1)+1) = (x+6, y+2)
and again ...
T³(x, y) = T(T²(x, y)) = T(x+6, y+2) = ((x+6)+3, (y+2)+1)
T³(x, y) = (x +9, y +3)