Thread: factor theorem

Factorise

I know that the constant term for this equation is -6 . Then , if (x-a) were to be a factor of P(x) , then a must be a factor of -6 .

Why is it so ? My book doesn't further explain .

Originally Posted by mathaddict

Factorise

I know that the constant term for this equation is -6 . Then , if (x-a) were to be a factor of P(x) , then a must be a factor of -6 .

Why is it so ? My book doesn't further explain .

Because when you put it in the form:



Then a and c must multiply to give -6, and hence both must be factors.