When you created your table to see if the resulting ordered pairs matched the graph, you may not have noticed that this function contains the term $\displaystyle-{3}{x}\usepackage{cmbright}\Huge\$ , not $\displaystyle{3}{x}\usepackage{cmbright}\Huge\$ . The graph of $\displaystyle{f{{\left({x}\right)}}}=-{3}{x}-{3}\usepackage{cmbright}\Huge\$ would contain the points $\displaystyle{\left(-{1},{0}\right)}\usepackage{cmbright}\Huge\$ and $\displaystyle{\left({1},-{6}\right)}\usepackage{cmbright}\Huge\$ , which are not on the given graph. The correct answer is $\displaystyle{f{{\left({x}\right)}}}={3}{x}-{3}\usepackage{cmbright}\Huge\$ .