## Elementary Algebra

To factor a trinomial in the form $x^2+bx+c$, we must find two numbers whose product is $c$ and whose sum is $b$. We then insert these two numbers into the blanks of the factors $(x+\_)(x+\_)$. In the case of $x^2-8x-36$, we are looking for two numbers whose product is $-36$ and whose sum is $-8$. Unfortunately, there are no integers that meet these criteria, so this expression is not factorable using integers.