1. **State the problem:** Solve the equation $$5 = x + 1 + 3x$$ for $$x$$. 2. **Combine like terms:** On the right side, combine $$x$$ and $$3x$$ to get $$4x$$. $$5 = 4x + 1$$ 3. **Isolate the term with $$x$$:** Subtract 1 from both sides. $$5 - 1 = 4x + 1 - 1$$ $$4 = 4x$$ 4. **Divide both sides by 4 to solve for $$x$$:** $$\frac{4}{\cancel{4}} = \frac{4x}{\cancel{4}}$$ $$1 = x$$ 5. **Final answer:** $$x = 1$$