int 3^(2x) * (2 - x) dx = int 9^x * (2 - x) dx = int (2 - x) d(9^x/ln 9) =
= 1/ln 9 * int (2 - x) d(9^x) = 1/ln 9 * (2 - x) * 9^x - 1/ln 9 * int 9^x d(2 - x) =
= 1/ln 9 * (2 - x) * 9^x + 1/ln 9 * int 9^x dx =
= 1/ln 9 * (2 - x) * 9^x + 1/ln^2 9 * 9^x + C