Graphs of Linear Functions and Rate of Change

The exercise has students look for and make use of structure while solving multi-step equations. A function is said to be linear if the rule defining the function can be described by a linear equation. Revisit the Opening Exercise at the end of the discussion so students can verify if their conjectures were correct. Make sure they recall that the graph of a numerical function is the set of ordered pairs (x, y) with x an input of the function and y its corresponding output.