Tìm x biết: 6x^2 – (2x – 3)(3x + 2) – 1 = 0.
Giải thích
6x2 – (2x – 3)(3x + 2) – 1 = 0
⇔ 6x2 – (6x2 – 5x – 6) – 1 = 0
⇔ 6x2 – 6x2 + 5x + 6 – 1 = 0
⇔ 5x + 5 = 0
⇔ x = – 1
Vậy x = – 1.
6x2 – (2x – 3)(3x + 2) – 1 = 0
⇔ 6x2 – (6x2 – 5x – 6) – 1 = 0
⇔ 6x2 – 6x2 + 5x + 6 – 1 = 0
⇔ 5x + 5 = 0
⇔ x = – 1
Vậy x = – 1.