Factor the expression

9x^2-16

(3x-4) (3x+4)

Step-by-step explanation:

9x^2-16

9x^2 is a product of squares = (3x) ^2

16 is a product of squares = 4^2

so

9x^2-16 is the difference of squares

(a^2 - b^2) = (a-b) (a+b) where a = 3x and b = 4

9x^2-16 = (3x-4) (3x+4)