Railways PYQCBT 1 2016

RRB NTPC · Question 35

\({\left( {4x - 7} \right)^2} = \;?\) A. 4x^2 – 56x + 49 B. 4x^2 – 14x + 49 C. 16x^2 + 14x + 49 D. 16x^2 – 56x + 49

  1. B

  2. A

  3. C

  4. D

Show answer & explanation

Answer: (D) D

Explanation

(a − b)² = a² − 2ab + b². With a = 4x and b = 7: 16x² − 56x + 49.