You need to factor the radicals into products of radicals, and when factoring you should keep in mind you want to obtain perfect square roots. So √125 = √5*√25 and squareroot 25 has a definite answer of 5, so ∛125=∛5×∛25=5×√5. You want to follow the general pattern of factoring perfect squares to obtain a number outside the radical which can be multiplied by the current coefficient