Answer:
A -6 < x ≤ -3
Step-by-step explanation:
21 ≤ - 3(x - 4) < 30
Divide all parts by -3. Remember that flips the inequalities
21/-3 ≥ - 3/-3 (x - 4) > 30/-3
-7 ≥ (x - 4) > -10
Add 4 to all sides
-7+4 ≥ x - 4+4 > -10+4
-3 ≥ x > -6
Rearranging the order
-6 < x ≤ -3
