Question 765094
(x + 3y) (x - 3y)

x * x = x^2

x * -3y = -3xy

3y * x = 3xy

3y * -3y = -9y^2

Therefore:

x^2 - 3xy + 3xy - 9y^2

Combine like terms:

-3xy + 3xy = 0


Answer:

x^2 - 9y^2










Lennox Obuong
Algebra Tutor
Nairobi, Kenya
Email: lennoxobuong@yahoo.com