Which polynomial is a perfect square trinomial? 25x2 − 20x − 16 9a2 − 30a − 25 25b2 − 15b + 9 16x2 − 24x + 9

16x² - 24x + 9 is a perfect square trinomial.

Step-by-step 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.

45 minutes

step-by-step explanation:

12

step-by-step explanation:

a triangle's   full angle is 180 degrees so 180 - 156 = 24. 24/2=12