How do you factorise x^2 - 4?

x^2 - 4 consider that in any quadratic the two numbers which end up in the brackets at the end must add up to the middle term in x. they must also multiply to make the number at the end of the quadratic termas there is no term in just x, we can put one in of 0therefore we can consider this question as x^2 + 0x - 4.Now we need to consider which numbers add up to 0, but also multiply to make -4. These two numbers are +2 and -2now we can rewrite the equation as x^2 +2x -2x -4.Now we take out common factors so, x(x+2) - 2(x+2).Therefore we can now see x^2 - 4 = (x+2)(x-2)