Perform the indicated operation. (3a2 - 7xy) (3a2 + 7xy)

(3a² - 7xy) (3a² + 7xy) =

= (3a²) ² - (7xy) ²

= 9a⁴ - 49x²y²

Use

a² - b² = (a - b) (a + b)

9a^4 - 49x^2y^2.

Step-by-step explanation:

(3a^2 - 7xy) (3a^2 + 7xy)

This is example of the difference of 2 squares:

(a + b) (a - b) = a^2 - b^2, so the answer is:

(3a^2) ^2 - (7xy) ^2

= 9a^4 - 49x^2y^2.