Factories the following expression-

25x² + 9y² – 30xy

In the given expression

1^st and last terms are perfect square

⇒ 25x² = 5x × 5x

⇒ 9y² = 3y × 3y

And the middle expression is in form of 2ab

30xy = 2 × 5x × 3y

∴ 5x × 5x + 2 × 3y × 5x + 3y × 3y

Gives (a-b)² = a²-2ab + b²

⇒ In 25x² – 30xy + 9y²

a = 5x and b = 3y;

∴ 25x² - 30xy + 9y² = (5x-3y)²

Hence the factors of 25x² - 30xy + 9y² are (5x-3y) and (5x-3y)