Question

$1)y^2 - x^2 - 6x - 9 \\ 2)2a - ac - 2c + c^2 \\ 3)bx + by - x - y - ax - ay \\ 4)x^2y - x^2 - xy + x^3$

Answer 1

1)(y-x-3)*(y+x+3)
2)(2-x)*(a-c)
3)(bx + by) - (x + y) - (ax +ay) = b(x + y) - (x +y) - a(x +y) = (x + y)(b - 1 - a)
4)x(x-1)(y+x)