Question

What is the y intercept of the linear equation x

Answer 1

0,0 is the equation of the y intercept

Answer 2

x isn't a linear equation, it's just a variable or an expression or a letter of the alphabet.

x = 0 is a linear equation and is a line in the Cartesian plane. In fact, it's the y axis itself.

So every point on the line x=0 is a y intercept.

There is no "the" y intercept, no unique y intercept.