Students identify independent and dependent variables and distinguish linear relationships by their constant rate of change, including positive, negative, and zero rates and proportional and nonproportional relationships. They represent and interpret linear relationships in tables, graphs, equations, and contexts, determining rate of change from $\Delta y/\Delta x$, identifying the initial value, and connecting these features to $y=mx+b$. They graph linear equations, write equations from tables and graphs using whole-number or simple fractional slopes, and compare relationships by matching inputs and outputs and interpreting their rates of change and initial values, including when the relationships intersect.