1. **State the problem:** Solve the equation $p + 2p + (p - 2) = 18$ for $p$. 2. **Combine like terms:** Add all the $p$ terms together and simplify the constants. $$p + 2p + p - 2 = 18$$ $$ (p + 2p + p) - 2 = 18$$ $$4p - 2 = 18$$ 3. **Isolate the variable term:** Add 2 to both sides to move the constant term. $$4p - 2 + 2 = 18 + 2$$ $$4p = 20$$ 4. **Solve for $p$:** Divide both sides by 4. $$\frac{\cancel{4}p}{\cancel{4}} = \frac{20}{4}$$ $$p = 5$$ 5. **Final answer:** The solution to the equation is $p = 5$.