Question

prove that (9xy - 3z)² - (9xy + 3z)² = -108xy²​

Answer 1

*Correct Question

• Show that (9xy - 3z)² - (9xy + 3z)² = -108xyz

(9xy - 3z)² - (9xy + 3z)²

= 9(3xy - z)² - 9(3xy + z)²

= 9{(3xy - z)² - (3xy + z)²}

= 9{(9x²y² - 6xyz + z²) - (9x²y² + 6xyz + z²)}

= 9(-12xyz)

= -108xyz

Now it is shown that the equality is true.

If you noticed the equality is always true, you might also know that it is an identity. Identity is equality which is always true.

Answer 2

Answer:

my question is (9xy+3z)2