The expression you've provided is:

$x^2 + xy + y^3$

This is a polynomial expression involving two variables, $x$ and $y$. Here's a breakdown of the terms:

1. $x^2$ is a quadratic term in $x$.
2. $xy$ is a cross-term involving both $x$ and $y$.
3. $y^3$ is a cubic term in $y$.

If you want to perform any operation on this expression (e.g., factoring, simplifying, differentiating), let me know.

Would you like more details or have any specific operations you'd like to perform on this expression?

Here are 5 related questions:

1. How would you differentiate this expression with respect to $x$?
2. How would you differentiate this expression with respect to $y$?
3. Can this expression be factored over real numbers?
4. What are the critical points of this expression if treated as a function $f(x, y)$?
5. How does the expression behave as $x$ and $y$ approach infinity?

Tip: Polynomials in two variables can represent surfaces in 3D space. Understanding their shape helps in visualizing mathematical functions.