2 câu trả lời
\(\begin{array}{l} \Leftrightarrow {x^2} - 4x - 5 - \left( {{x^2} - x - 6} \right) = 14\\ \Leftrightarrow - 3x = 13\\ \Leftrightarrow x = - \dfrac{{13}}{3} \end{array}\)
(x+1)(x-5)-(x+2)(x-3)=14
⇔ x ² - 5x + x - 5 - (x ² - 3x +2x - 6) = 14
⇔ x ² - 5x + x - 5 - x ² + 3x - 2x + 6 = 14
⇔ -3x + 1 = 14
⇔ -3x = 13 (do 14 - 1)
⇔ x = -13/3