Sigrid Wagner, Conservation of Equation and Function under Transformations of Variable, Journal for Research in Mathematics Education, Vol. 12, No. 2 (Mar., 1981), pp. 107-118 ...

Ruth M. Steinberg, D. H. Sleeman, David Ktorza, Algebra Students' Knowledge of Equivalence of Equations, Journal for Research in Mathematics Education, Vol. 22, No. 2 ...

Linear relationships can be expressed either in a graphical format or as a mathematical equation of the form y = mx + b. Linear functions are widely used in economics, physics, finance, and data ...