1. To simplify a radical expression, group all terms so that the radicand only contains factors with powers less than the index. The index should be as small as possible and the denominator rationalized by removing radicals. 2. Radical expressions can be combined by using properties of radicals, like the product property. Terms with the same radicand and index can be combined by adding the coefficients. 3. For an expression to be in simplest form, the radicand must have powers less than the index, the index is as small as possible, the denominator is rationalized, and there are no fractions under the radical.