# Thread: Factoring Question

1. ## Factoring Question

pretty easy question.. can't get answer in the back of the book though.

x2 + 6y -y2 -9

(x-3)(x+3) + y(6-y)

back of book
(x+y-3)(x-y+3)

2. $\displaystyle x^2 + 6y -y^2 -9$

$\displaystyle x^2 -y^2 + 6y-9$

$\displaystyle x^2 -(y^2 - 6y+9)$

$\displaystyle x^2 -(y- 3)^2$

Using the difference of two squares rule.

$\displaystyle (x -(y- 3))(x +(y- 3))$

$\displaystyle (x -y+ 3)(x +y- 3)$

3. lol cant believe i missed that, thanks.