What characterizes a linear equation?

A linear equation is characterized by its ability to graph as a straight line on a Cartesian coordinate system. This arises from the structure of a linear equation, which typically can be expressed in the standard form (y = mx + b), where (m) represents the slope and (b) represents the y-intercept. This equation involves only first-degree terms, meaning that the variables are not raised to any powers other than one, and there are no products of variables.

When graphed, the slope indicates the steepness of the line, while the y-intercept indicates the point where the line crosses the y-axis. This consistent relationship between the variables leads to the straight-line graph characteristic of all linear equations. Thus, the option indicating that a linear equation graphs to a straight line correctly encapsulates this essential property of linear equations.