Chapter 2 - Systems of Linear Equations and Inequalities - 2.2 Solving Systems of Equations Using the Substitution Method - 2.2 Exercises - Page 154: 54

Infinite number of solutions (consistent dependent system)

Rewrite the given system in the slope intercept form to see what properties it has. $$\begin{cases} d &= -6(c-4)-10\\ &= -6c+14\\ d& =-6(c+2)+26\\ &= -6c+14 \end{cases}$$ We are asked to use the method of substitution to solve the given system. However, we see that both equations are identical. It follows that the system is consistent with dependent lines and has an infinite number of solutions.