You have two expressions in each of which is equal to . They can't both be equal to without being equal to each other, can they? Set the two expressions in equal to each other, collect like terms all in the LHS leaving the resulting quadratic trinomial in equal to zero. Solve the quadratic for its two roots, if they exist. Hint: The resulting quadratic is factorable over the integers.
My calculator said it, I believe it, that settles it