Respuesta :

Answer:

4g² - 36gh + 81h²

Step-by-step explanation:

Apply the perfect square formula: (a - b)² = a² - 2ab + b²

(2g - 9h)²​ = (2g)² - 2(2g)(9h) + (9h)²

Simplify:

2g² = 4g²

-2 · 2g = -4g · 9h = -36gh

9h² = 81h²

= 4g² - 36gh + 81h²

hope this helps!