Solve 4x² - 9 = 0 — x = 3/2 or x = -3/2

Problem

$4x^2 - 9 = 0$

Step-by-step solution

辨認為平方差： $4x^2 = (2x)^2$ 且 $9 = 3^2$ 。
因式分解： $(2x - 3)(2x + 3) = 0$ 。
令每個因式為零： $2x - 3 = 0$ 或 $2x + 3 = 0$ 。
求解： $x = \tfrac{3}{2}$ 或 $x = -\tfrac{3}{2}$ 。

Answer

$x = \tfrac{3}{2} \quad \text{or} \quad x = -\tfrac{3}{2}$

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