Final answer:
A linear function is a mathematical function in which the equation representing the function is a linear equation. In the given equation 3y - 4x = 20, both terms y and x have an exponent of 1, making it a linear equation.
Step-by-step explanation:
A linear function is a mathematical function in which the equation representing the function is a linear equation. A linear equation is an equation with degree 1, meaning that the highest exponent on the variable is 1. In the given equation 3y - 4x = 20, both terms y and x have an exponent of 1, making it a linear equation.