What is the x-intercept of a line?

• A. The point where the line crosses the x-axis
• B. The point where the line crosses the y-axis
• C. The slope of the line
• D. The y-coordinate of the origin

Answer: (A)

The x-intercept is the point where the line meets the x-axis, which is where the y-coordinate is zero. On the graph, that point has coordinates (x0, 0), representing the x-value where the line crosses the axis. If the line crosses at x = 5, the x-intercept is 5. If the line never crosses the x-axis (a horizontal line above or below it), there is no x-intercept. If the line lies on the x-axis itself, every point on the line is an x-intercept.

This is different from where the line crosses the y-axis (that would be the y-intercept), from the slope (which measures steepness), and from the origin (the specific point (0,0)).