Explanation:
1st : Vector translation.
a vector -8j ( 0 , -8 ) helped translate (x , y) => (x , y - 8)
2nd : rotation.
The only rotation that results in (-x , -y) is pi rotation.
formula : (x , y -8) => ( xcos(pi) - ysin(pi) , xsin(pi) + ycos(pi) )
substitute x & y-8 into x & y respectively of the formula above.