Final answer:
To solve the compound inequality a + 12 ≤ -36 or a - 7 ≥ 28, we solve each individual inequality and combine their solutions to get a ≤ -48 or a ≥ 35.
Step-by-step explanation:
To solve the given compound inequality, we will solve each individual inequality and then combine their solutions.
First, let's solve the inequality a + 12 ≤ -36. Subtracting 12 from both sides, we get a ≤ -48.
Next, let's solve the inequality a - 7 ≥ 28. Adding 7 to both sides, we get a ≥ 35.
Combining the two solutions, the compound inequality is a ≤ -48 or a ≥ 35, which is option D.