Tìm x, biết: 4x² – 25 – (2x – 5)(2x + 7) = 0.

4x² – 25 – (2x – 5)(2x + 7) = 0

⇔ (4x² – 25) – (2x – 5)(2x + 7) = 0

⇔ (2x – 5)(2x + 5) – (2x – 5)(2x + 7) = 0

⇔ (2x – 5)(2x + 5 – 2x – 7) = 0

⇔ (2x – 5).(–2) = 0

⇔ 2x – 5 = 0

⇔ \(x = \frac{5}{2}\)

Vậy \(x = \frac{5}{2}\).