Concept:Use exponent rules to combine the radicals into a single square root of a product.Explanation:Write each square root as a power of 21: x−1y⋅y−1z⋅z−1x=(x−1y)21⋅(y−1z)21⋅(z−1x)21.Combine the exponents: (x−1y⋅y−1z⋅z−1x)21.Multiply inside: x−1⋅x=1, y⋅y−1=1, z⋅z−1=1, so product =1⋅1⋅1=1.Thus the expression becomes 121=1.Answer:1