Algebrahard · Past Paper
Solve for x: x^4 - 13x^2 + 36 = 0.
A±2, ±3
B2, 3
C±4, ±9
D4, 9
✓ Correct Answer: A — ±2, ±3
Let y = x^2. y^2 - 13y + 36 = 0 → (y-4)(y-9) = 0. x^2=4 → x=±2; x^2=9 → x=±3.
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✓ Correct Answer: A — ±2, ±3
Let y = x^2. y^2 - 13y + 36 = 0 → (y-4)(y-9) = 0. x^2=4 → x=±2; x^2=9 → x=±3.
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