#### Answer

$$4x^2y^{\sqrt{2}}$$

#### Work Step by Step

In order to solve this problem, we must use the rules of rational exponents, which are listed on page 420. (Note, we may have to change the rational expressions so that they have rational exponents using the tools learned in 6.1.) Doing this, we find that the expression simplifies to:
$$x^2y^{\sqrt{2}}+3x^2y^{\sqrt{2}} \\ 4x^2y^{\sqrt{2}}$$