How to to factorise double brackets, factoring expressions of the form x^2+ax+b
The numbers multiply to make b and add to make a, and this allows us to factorise quadratic expressions involving two brackets.
ex 1) Factorise x^2+7x+12 = (x+4)(x+3)
ex 2) Factorise x^2+9x+20=(x+4)(x+5)
ex 3) Factorise x^2+7x+6=(x+6)(x+1)
ex 4) Factorise x^2+5x-14=(x+7)(x-2)
ex 5) Factorise x^2+7x-18=(x+9)(x-2)
ex 6) Factorise x^2-3x-10=(x+2)(x-5)
Then some extension questions were there is an x which we write as 1x or -x which we write as -1x
Also, two example of the difference of two squares
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