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How Do I Factorise In Maths?

I really don’t get factorising, I’m doing a GCSE past paper and I have this question:

factorise x² -6x + 8

Could someone explain how to do it please, not just give me the answer?

Thanks xx

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Answer #1

I think voxx meant (x-4) (x-2)

Answer #2

You look at numbers that will multiply into +8 and will add up into -6

First just do the numbers, 1 x 8 2 x 4

well that’s about it. But it has to multiply to + 8

1 x 8 = 8 -1 x - 8 = 8 so 2 x 4 = 8 -2 x -4 = 8

now it also has to add to -6

1 + 8 = 9 -1 + - 8 = -9 2 + 4 = 6 -2 + -4 = -6

(x-2) (x-4) = x2 - 4x - 2x + 8 = x2 - 6x + 8

It will get faster once you can do it in your head, but those are the steps for now.

Answer #3

In addition to the person above, you’d write the answer like this: (x-4)(x+2) Since there are two x’s(x squared equals x times x), you need two x’s in the answer…hope that makes sense. :)

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