Correct. Combining the areas of the two sections of the field gives us $\displaystyle{5}{{x}}^{{2}}-{x}{y}+{40}{x}{y}-{8}{{y}}^{{2}}\usepackage{cmbright}\Huge\$ , or $\displaystyle{5}{{x}}^{{2}}+{39}{x}{y}-{8}{{y}}^{{2}}\usepackage{cmbright}\Huge\$ .