Solve 4x² - 9 = 0

Problem

$4x^2 - 9 = 0$

Step-by-step solution

Recognise as difference of squares: $4x^2 = (2x)^2$ and $9 = 3^2$ .
Factor: $(2x - 3)(2x + 3) = 0$ .
Set each factor to zero: $2x - 3 = 0$ or $2x + 3 = 0$ .
Solve: $x = \tfrac{3}{2}$ or $x = -\tfrac{3}{2}$ .

Answer

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

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