ECZ 2013 · O-Level Paper 1 — Quadratic Equations

Solve the equation (x - 1)(x + 1) = 8.

  • A. x = 3
  • B. x = 3 or x = -3
  • C. x = 9 or x = -9
  • D. x = sqrt(7) or x = -sqrt(7)

Verified working — step 1

The left side is the difference of two squares: x2 - 1 = 8, so x2 = 9 and x = 3 or x = …

The full step-by-step working and final answer are included with Premium — checked against ECZ marking standards.

Original examination question © Examinations Council of Zambia. Worked solution and commentary © G12 Titan — not to be reproduced without permission.

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