Which equation is a linear function

Step-by-step explanation:

Linear functions are those whose graph is a straight line.

A linear function has the following form:

A linear function has one independent variable and one dependent variable.

The independent variable is x and the dependent variable is y.

The degree of a linear equation must be 0 or 1 for each of its variables.

1. The degree of the variable y is 1 which means it is not linear.

2. The degree of the variable y is 1 and the degree of variable x is 1 so it is linear.

3. The degree of the variable y is 1 and the degree of the variable x is 2 so it is not linear.

4. The degrees of the variable violates the linear equation definition so it is not linear.

a

step-by-step explanation: