ECZ 2014 · O-Level Paper 1 — Algebra
Factorise completely 5x² − x − 4.
- A. (5x + 4)(x − 1)
- B. (5x − 4)(x + 1)
- C. (x + 4)(5x − 1)
- D. (5x + 2)(x − 2)
Verified working — step 1
Two numbers multiplying to 5 × −4 = −20 and adding to −1 are −5 and 4. Split: 5x² − 5x + 4x − 4 = 5x(x − 1) + 4(x − 1) = …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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