passwella.
Menu

JAMB Mathematics 1999 Question 15

Question 15

Matrices and Determinants

Given that Q = (6 0 / 4 5) and Q + P = (7 −2 / 6 8), evaluate |Q + 2P|. (Rows are separated by /.)

  1. A.90
  2. B.96
  3. C.102
  4. D.120
Show the answer and explanation

Answer: D (120)

Explanation

P = (1 −2 / 2 3), so Q + 2P = (8 −4 / 8 11). Its determinant is 8 × 11 − (−4)(8) = 88 + 32 = 120.