1. **State the problem:** Translate the sentence "The sum of 3 and y is less than or equal to -20" into an inequality. 2. **Identify the sum:** The sum of 3 and y is written as $3 + y$. 3. **Translate the phrase "is less than or equal to":** This corresponds to the inequality symbol $\leq$. 4. **Write the inequality:** Combine the sum and the inequality symbol with the number on the right side: $$3 + y \leq -20$$ 5. **Isolate $y$ to better understand the inequality:** $$3 + y \leq -20$$ Subtract 3 from both sides: $$\cancel{3} + y - \cancel{3} \leq -20 - 3$$ Simplifies to: $$y \leq -23$$ 6. **Interpretation:** The variable $y$ must be less than or equal to $-23$. 7. **Choose the correct inequality symbol from the options:** The correct symbol is $\leq 0$ (less than or equal to zero) when comparing the sum minus the right side, but since the inequality is $3 + y \leq -20$, the correct choice is $\leq 0$ if we rewrite as $3 + y + 20 \leq 0$ or simply recognize the phrase "less than or equal to". **Final inequality:** $$3 + y \leq -20$$