If |x 2; 8 x| = |4 1; 3 2|, then x is:

If |x 2; 8 x| = |4 1; 3 2|, then x is:

• A. ±√21
• B. ±3
• C. ±5
• D. ±√13

Answer: A) ±√21

Explanation: LHS = x² − 16. RHS = 8 − 3 = 5. So x² = 21 → x = ±√21.