ECZ 2015 · O-Level Paper 1 — Relations and Functions
Given that f(x) = 2x + 78and g(x) = 3x − 66, find f⁻¹(x).
- A. 8x − 72
- B. 8x + 72
- C. 82x + 7
- D. 2x − 78
Verified working — step 1
Let y = 2x + 78. Interchange and solve: x = 2y + 78⇒ 8x = 2y + 7 ⇒ y = …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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