Chapter 5 - Polynomials and Factoring - 5.3 Factoring Trinomials of the Type ax2+bx+c - 5.3 Exercise Set - Page 327: 87

Answers vary.

One way you could do this is by having them list out all of the factors of the constant term. Then, they would have to find the numbers that add to get the $a$ in the $ax$ term and multiplies to get the constant term. This would help them see that the given trinomial is prime.