Multiply. (3x + 5) (3x - 5)

To multiply (3x + 5) and (3x - 5), we can use the foil method:

(3x + 5) (3x - 5) = 3x * 3x + 3x * (-5) + 5 * 3x + 5 * (-5)
= 9x^2 - 15x + 15x - 25
= 9x^2 - 25

Therefore, (3x + 5) (3x - 5) = 9x^2 - 25.