blackpenredpen's video: Explanation of why x^2 + x - 5 is a factor: The solution to this competition problem using a quadratic equation in "5" is awesome. How can we solve it without that method? Here we use some other strategies to actually find the solutions to the quartic polynomial after squaring both sides! Check out more challenge problems here: Subscribe to see more new math videos! Music: OcularNebula - The Lopez