You may have confused dependent and independent or graphed the lines incorrectly. The graphs of these equations are lines that intersect in one point, so the equations are independent. The correct answer is $\displaystyle{2}{x}-{y}={5}\usepackage{cmbright}\Huge\$ and $\displaystyle{4}{x}-{2}{y}={10}\usepackage{cmbright}\Huge\$ .