Which term is the horizontal number line in a coordinate plane?

Which term is the horizontal number line in a coordinate plane?

• A. Units
• B. X-axis
• C. Axis labels
• D. Y-axis

Answer: (B)

In a coordinate plane, the line that runs left to right is the x-axis. It shows horizontal positions, so as you move along it you’re changing the x-value while the y-value stays the same. Points on the plane are written as (x, y), with x representing the horizontal distance from the origin and y representing the vertical distance. The vertical line that goes up and down is the y-axis. The other terms describe the scale and markings on the axes—units are the intervals between tick marks, and axis labels are the numbers that show those intervals. In short, the horizontal line is the x-axis.

In a coordinate plane, the line that runs left to right is the x-axis. It shows horizontal positions, so as you move along it you’re changing the x-value while the y-value stays the same. Points on the plane are written as (x, y), with x representing the horizontal distance from the origin and y representing the vertical distance. The vertical line that goes up and down is the y-axis. The other terms describe the scale and markings on the axes—units are the intervals between tick marks, and axis labels are the numbers that show those intervals. In short, the horizontal line is the x-axis.