4.28. 7x² + 9x + 2 = 0

Question

Дискриминант: \(D=9^2-4\cdot7\cdot2=25\), \(\sqrt D=5\).

\(x=\frac{-9\pm5}{14}\).

\(x_1=\frac{-9+5}{14}=-\frac27\), \(x_2=\frac{-9-5}{14}=-1\).

Ответ: \(x_1=-\frac27\), \(x_2=-1\).

Accepted Answer

Дискриминант: \(D=9^2-4\cdot7\cdot2=25\), \(\sqrt D=5\).

\(x=\frac{-9\pm5}{14}\).

\(x_1=\frac{-9+5}{14}=-\frac27\), \(x_2=\frac{-9-5}{14}=-1\).

Ответ: \(x_1=-\frac27\), \(x_2=-1\).