1. Write as an algebraic equation:
12 + n ≤ 2n - 8
2. Solve for n.
12 + n - 12 ≤ 2n - 8 - 12
n ≤ 2n - 20
n - 2n ≤ 2n - 20 - 2n
-n ≤ -20
Multiply both sides by -1 (this means you must flip the inequality sign).
n ≥ 20
FINAL ANSWER: n ≥ 20
Hope this helps! Feel free to ask for clarification.