25a^2 - 30a + 9
That means that the factors will be somewhere in (25a-1)(a-9) (25a-3)(a-3) (25a-9)(a-1) (5a-1)(5a-9) (5a-3)(5a-3) <----- (5a-9)(5a-1) Review your FOIL rules if it's not clear why this is the correct factorization.
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