how do you know if a straight line equation is parallel to the x or y axis

If the equation is in the form y = mx + b, where m is the slope and b is the y-intercept, then the line is parallel to the x-axis if m = 0. This means that the line is horizontal and does not slope up or down.

If the equation is in the form x = c, where c is a constant, then the line is parallel to the y-axis. This means that the line is vertical and does not slope to the left or right.