First multiply 4p by 4p from the other parenthesis. Then multiply the same 4p with -1 from the second parenthesis. Then do the same with the -1 from the first parenthesis.
Then you get:
4p×4p + 4p×(-1) + (-1)×4p + (-1)×(-1) =
16p^2 - 4p - 4p + 1 =
16p^2 - 8p + 1.
