Solve 4x² - 25 = 0 — x = 5/2 or x = -5/2

Problem

$4x^2 - 25 = 0$

Step-by-step solution

辨認為平方差： $4x^2 = (2x)^2$ ， $25 = 5^2$ 。
分解： $(2x - 5)(2x + 5) = 0$ 。
求解： $x = \tfrac{5}{2}$ 或 $x = -\tfrac{5}{2}$ 。

Answer

$x = \tfrac{5}{2} \quad \text{or} \quad x = -\tfrac{5}{2}$

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