1) (a^2 - 9b^2)/(a + 3b) = ((a - 3b)(a + 3b))/(a + 3b) = a - 3b
2) (x^3 - 8)/(x - 2) = (x - 2)(x^2 + 2x + 4)/(x - 2) = x^2 + 2x + 4
3) (y - 2x)/(y^2 - 4xy + 4x^2) = (y - 2x)/((y - 2x)(y - 2x)) = 1/(y - 2x)
4) (a^2 + 6a + 9)/(a^2 - 9) = ((a + 3)(a + 3))/((a + 3)(a - 3)) = (a + 3)/(a - 3)
1) (a^2 - 9b^2)/(a + 3b) = ((a - 3b)(a + 3b))/(a + 3b) = a - 3b
2) (x^3 - 8)/(x - 2) = (x - 2)(x^2 + 2x + 4)/(x - 2) = x^2 + 2x + 4
3) (y - 2x)/(y^2 - 4xy + 4x^2) = (y - 2x)/((y - 2x)(y - 2x)) = 1/(y - 2x)
4) (a^2 + 6a + 9)/(a^2 - 9) = ((a + 3)(a + 3))/((a + 3)(a - 3)) = (a + 3)/(a - 3)