1. Plug the coordinates into the translation given: A(3,2) -> A'(3+6, 2-3) => A'(9, -1)
2. To find the preimage, you do the opposite: C'(2, -7) -> C(2-6, -7+3) => C(-4, -4)
3. Do the same as #1: B'(-4+6, 1-3) => B'(2, -2)
4. Do the same as #2: D(-3-6, -2+3) => D(-9, 1)