Question

is 81a^2 - 72ab + 16b^2 a perfect trinomial square​

Answer 1

Yes.

By identity, (9a)² - 2×(9a)×(4b) + (4b)² is a perfect square of (9a-4b).

Answer 2

Answer:

 (9a - 4b)2

Step-by-step explanation:

((81 • (a2)) -  72ab) +  24b2

(34a2 -  72ab) +  24b2

(9a - 4b)•(9a - 4b)

(9a - 4b)2