Ever wonder what sorts of errors freshman math students make? There are a couple of pretty basic ones.

A linear equation is drawn as a straight line on a set of axes. To draw the graph we need coordinates. We generate these coordinates by substituting values into the linear equation.

Pamela J. Wells, Understanding Linear Functions and Their Representations, Mathematics Teaching in the Middle School, Vol. 21, No. 5 (December 2015/January 2016), pp. 308-316 ...