Final Answer:
The linear equation is a. y = x.
Step-by-step explanation:
A linear equation is an equation of the form y = mx + b, where m and b are constants. This means that the relationship between x and y is a straight line.
Let's analyze each option:
a. y = x: This equation clearly follows the format y = mx + b, where m = 1 and b = 0. Therefore, it is a linear equation.
b. y = | x |: This equation represents the absolute value function, which is not a straight line. Therefore, it is not a linear equation.
c. y = x²: This equation represents the quadratic function, which is a curve and not a straight line. Therefore, it is not a linear equation.
d. y = x√: This equation represents the square root function, which is also not a straight line. Therefore, it is not a linear equation.
Therefore, the only option that represents a linear equation is a. y = x.