1. **State the problem:** Solve the inequality $x + 5.4 < -1.6$. 2. **Write the inequality:** $$x + 5.4 < -1.6$$ 3. **Isolate $x$ by subtracting 5.4 from both sides:** $$x + 5.4 - \cancel{5.4} < -1.6 - \cancel{5.4}$$ 4. **Simplify the right side:** $$x < -1.6 - 5.4$$ $$x < -7.0$$ 5. **Interpretation:** The solution is all values of $x$ less than $-7.0$. 6. **Graphical representation:** On a number line, this is shown as a shaded region extending leftwards from $-7.0$, with an open circle at $-7.0$ because the inequality is strict (less than, not less than or equal to).