1. **State the problem:** Solve the equation $$42 = 18 - 4l$$ for $l$. 2. **Isolate the term with $l$:** Subtract 18 from both sides: $$42 - 18 = 18 - 4l - 18$$ $$24 = -4l$$ 3. **Divide both sides by $-4$ to solve for $l$:** $$l = \frac{24}{\cancel{-4}} \times \frac{\cancel{-1}}{1} = -6$$ 4. **Final answer:** $$l = -6$$ This completes the solution for the first equation.