Answer by
Joshered (10)

You cannot combine (add or subtract) radicals unless they are like (meaning the numbers under the radicals are the same), such as sqrt(3) + sqrt(3) = 2sqrt(3). Polynomials are expressions, but that do not have absolute value, any roots (such as square roots), or division by a variable. x + 3 is a polynomial, but 5/x + 3 is not.