Correct. Equations are dependent if their graphs are the same line. Therefore, the line shown is the graph of both equations. This line includes the point (5, 0), for example. If you substitute the coordinates of this point into the second equation, you will get $\displaystyle{2}{\left({5}\right)}-{4}{\left({0}\right)}\usepackage{cmbright}\Huge\$ . Simplifying tells you that the missing number is 10.