Answer:
(5a-3)(5a-3)
Explanation:
This will be a perfect square trinomial. To factor, we take the square root of the first term and the last term:
√25a² = 5a
√9 = 3
Since it is in the form ax²-bx+c, both binomials will be subtraction; this makes the factors
(5a-3)(5a-3)
To double check, multiply back through:
5a(5a)-3(5a)-3(5a)-3(-3)
25a²-15a-15a--9
25a²-30a+9