You probably did not create a table of values for this function to see if the resulting ordered pairs matched the graph. Instead, you may have chosen this function because the numbers 2 and 4 were in the expression and the graph contains the points $\displaystyle{\left({0},{4}\right)}\usepackage{cmbright}\Huge\$ and (2, 0). The correct answer is $\displaystyle{f{{\left({x}\right)}}}=-{2}{x}+{4}\usepackage{cmbright}\Huge\$ .