3. Solve: x-4leqslant 5 OR -3xlt -36 1 xleqslant 9 AND xlt 12 xleqslant 9 OR xgt 12 xleqslant 9 OR xlt 12 xleqslant 9 AND xgt 12

To solve the given compound inequality, we need to solve each inequality separately and then combine the solutions.The first inequality is . To solve for , we add to both sides of the inequality: Simplifying, we get: The second inequality is . To solve for , we divide both sides of the inequality by . Remember that when dividing or multiplying an inequality by a negative number, the direction of the inequality sign changes: Simplifying, we get: Now, we combine the solutions of the two inequalities. Since the compound inequality is connected by the word "OR", we take the union of the two solutions. This means that can satisfy either inequality.Therefore, the solution to the compound inequality is OR .