It appears that the document contains multiple-choice math questions, likely from an exam or practice sheet, with topics covering irrational numbers, simplification, expressions, and scientific notation.

Here’s a breakdown of how to approach a few questions from the document:

1. Identify Irrational Numbers:

   • This involves checking if each given number is irrational. For instance, numbers with repeating non-terminating decimals or non-perfect roots are often irrational.

2. Simplify Expressions:

   • For problems like "2² –," evaluate each component, applying order of operations.

3. Undefined Expressions:

   • Determine expressions where the operations (e.g., division by zero) make them undefined.

4. Match Terms to Properties:

   • Questions that ask to match numbers or expressions with properties like "positive," "negative," or "rational" involve understanding the sign and type of each expression.

5. Rationalizing Denominators:

   • Involves removing any irrational numbers from the denominator by multiplying with a conjugate or similar technique.

Would you like solutions to specific questions, or detailed explanations on the methodology for these types? Here are some further question options that may help:

1. How do we classify numbers as rational or irrational?
2. What are methods for simplifying expressions with variables?
3. Can we determine when an expression becomes undefined?
4. What steps help rationalize denominators in fractions?
5. How can scientific notation help in simplifying very large or small numbers?

Tip: In any calculation, double-check order of operations (PEMDAS/BODMAS), as it can greatly impact the result!