Respuesta :

altavistard

Answer:

9y^2 - 25

Step-by-step explanation:

This is the product of the sum and difference of two squares:

(a - b)(a + b) = a^2 - b^2 (a formula well worth memorizing)

Therefore, (3y - 5)(3y + 5) = 9y^2 - 25, which is in standard form.