Question

Question #6a04a

Answer 1

This is a well known pattern: `(xy-ab)(xy+ab) = (xy)^2-(ab)^2`
Because of the properties of exponents `(xy)^2-(ab)^2 = x^2y^2-a^2b^2`
Therefore, the final answer is: `(xy-ab)(xy+ab) = x^2y^2-a^2b^2`