Next, try to factor the trinomial into the product of two binomials, beginning with the . The only way to break this down is to say 2x *x. The signs will be opposite, since the last term is a -15.
Next, you need to find a combination of -15, what times what will come out to -15 in such a way that the outer times outer terms will subtract and give you a -1x for the middle term. The combination that works is 5 times -3, as follows:
, where the outer times outer is -6x and the inner times inner is +5x, for a total of -1x. That should do it:
