Answer:
16x² - 24x + 9 is a perfect square trinomial.
Explanation:
A quadratic polynomial ax²+bx+c is a perfect square trinomial,
If b² = 4ac,
In 25x² - 20x - 16,
(20)² ≠ 4 × 25 × -16
Thus, 25x² - 20x - 16 is not a perfect square trinomial,
In 9x² - 30x - 25,
(-30)² ≠ 4 × 9 × -25
Thus, 9x² - 30x - 25 is not a perfect square trinomial,
In 25b² - 15b + 9,
(-15)² ≠ 4 × 25 × 9
Thus, 25b² - 15b + 9 is not a perfect square trinomial,
In 16x² - 24x + 9,
(-24)²= 4 × 9 × 16
Thus, 16x² - 24x + 9 is a perfect square trinomial.