Your friend says that given a linear system with an equation of a horizontal line and an equation of a vertical line, you cannot solve the system by substitution. Is your friend correct? Responses No, because any system of linear equations can be solved by substitution. No, because any system of linear equations can be solved by substitution. No, because a system of linear equations with perpendicular lines can be solved by substitution. No, because a system of linear equations with perpendicular lines can be solved by substitution. Yes, because both equations only have 1 variable and the variables are different. Yes, because both equations only have 1 variable and the variables are different. Yes, because a system of linear equations with perpendicular lines cannot be solved by substitution.