Question

Which polynomial is a perfect square trinomial?

36x2 − 18x − 9
4a2 − 28a − 49
25b2 − 40b + 16
4x2 − 6x + 9

Answer 1

25b2-40b + 16

Explanation:

Hope It's Right !! Sorry if its really late

Answer 2

25b^2 - 40b + 16 = (5b - 4)(5b - 4)

so its the third choice