You have two x terms and two y terms in order to get x2 and y2. Since x2 has a coefficient of 1, it's safe to say that we're looking at (x + ay)(x + by), where a and b are y's coefficients. You need some combination of a and b that, when multiplied, makes -16. Your options are -1 and 16, 1 and -16, -2 and 8, 2 and -8, and 4 and -4. However, notice that you don't have anything to the first power in this equation. This means that the resulting "xy" terms must cancel out, and the only way to do that is if you have 4 and -4. So you get (x + 4y)(x - 4y).
It is: (x+5)(x-8) when factored
64-x2 = (8-x)(8+x) when factored
x2-4x-165 = (x-15)(x+11) when factored
x2 - 2x = x(x - 2)
It is x^2 -x -12 is (x+3)(x-4) when factored
It is: (x+5)(x-8) when factored
It is: (x+5)(x-8) when factored
64-x2 = (8-x)(8+x) when factored
x2-4x-165 = (x-15)(x+11) when factored
2x squared minus 5x minus 3 factored is (2x+1)(x-3).
It is: (x-2)(x-7) when factored
x2 - 2x = x(x - 2)
It is x^2 -x -12 is (x+3)(x-4) when factored
That can be factored to (x - 2)(x - 1)
x2-10x-24 = (x+2)(x-12) when factored
x2-5x-36 = (x-9)(x+4) when factored
(4+x) (2x-3)