passwella.
Menu

UI Post-UTME Mathematics 2012 Question 44

Question 44

Matrices and Determinants

Solve for x and y: (1 1; 3 y)(x; 1) = (4; 1) (matrix rows separated by semicolons)

  1. A.x = 3, y = 8
  2. B.x = 8, y = 3
  3. C.x = 3, y = −8
  4. D.x = 8, y = −3
Show the answer and explanation

Answer: C (x = 3, y = −8)

Explanation

x + 1 = 4 gives x = 3; 3x + y = 1 gives y = 1 − 9 = −8.