Factorise x^2+6x+8

Firstly, as it's highest term is x², it must only have two factor brackets, so the answer has to look like (x + a) * (x + b).Then, to make 6x, we need the a and b term to be either 5 and 1, 4 and 2, or 3 and 3, because they add up to make 6. If we look at ab, the only option that makes 8 (in the original question) is 42. So our factorisation must be(x + 4) * (x + 2).To check it, we do x * x = x² , 4x + 2x = 6x, and 4*2=8!