This self checking worksheet sets a radical equal to a variable: Sq rt(x^2 + 11x - 1) = 5x. To solve, the student will need to know how to factor a trinomial. There are solutions and extraneous solutions. Both are important in solving the riddle. The student must check their work and know which is the actual solution and which is the extraneous solution. Not all problems will have an actual solution (both may be extraneous). Some problems will have one actual solution and one extraneous solution. Others will have two actual solutions with no extraneous solutions. When finished, the student will discover how the old never die.