When we look at the trinomial, there is no number (coefficient) in front of x² , so we know that it is a simple trinomial. All you have to do in a simple trinomial is to find two numbers that not only add up to the b term, but multiply to the c term.
In this trinomial, the b term is 13 , so you need to find two numbers that add up to 13 . That could be
and so on. But these two numbers need to multiply to get the c term. In this case, it's 42 . So what two numbers add up to 13 and multiply to 42 ? The answer is 6 and 7 .
and
After this, all you need to do is put this in binomial form, so take an x , and add your first number