Demonstrating the Addition Property

The addition property for inequalities states that if an inequality exists, adding or subtracting the same number on both sides does not change the inequality.

1. ⓐ
   $\begin{array}{ll}x-15<4\hfill & \hfill \\ x-15+15<4+15\hfill & \text{Add 15 to both sides}.\hfill \\ x<19\hfill & \hfill \end{array}$
2. ⓑ
   $\begin{array}{ll}6\ge x-1\hfill & \hfill \\ 6+1\ge x-1+1\hfill & \text{Add 1 to both sides}.\hfill \\ 7\ge x\hfill & \hfill \end{array}$
3. ⓒ
   $\begin{array}{ll}x+7>9\hfill & \hfill \\ x+7-7>9-7\hfill & \text{Subtract 7 from both sides}.\hfill \\ x>2\hfill & \hfill \end{array}$