Step [tex]1[/tex]
Find the unit rates in Alpha printing
[tex]Unit\ Rate=\frac{20}{400} \frac{\$}{brochures} =0.05\frac{\$}{brochures}[/tex]
Step [tex]2[/tex]
Find the unit rates in Omega printing
[tex]Unit\ Rate=\frac{20}{1,000} \frac{\$}{brochures} =0.02\frac{\$}{brochures}[/tex]
Step [tex]3[/tex]
Find the difference of the unit rates
[tex]0.05\frac{\$}{brochures}-0.02\frac{\$}{brochures}=0.03\frac{\$}{brochures}[/tex]
therefore
the answer is
[tex]0.03\frac{\$}{brochures}[/tex]