How to determine if an equation is a linear relation

The video tutorial explores the concept of linear relations, focusing on function notation and criteria for identifying non-linear relations. It explains that a linear relation cannot have variables in the denominator or variables multiplied by each other. The tutorial also covers the importance of exponents being to the first power for a relation to be linear, using the example of H of X and its function notation.

How does the presence of multiplication between variables affect the classification of a relation as linear?

What does function notation imply about the variables involved in the function?