Question

Answer 1

\(\Delta=9-4\left(-1\right).12=9+48=57>0\)

pt có 2 nghiệm pb 

\(x_1=\dfrac{3-\sqrt{57}}{24};x_2=\dfrac{3+\sqrt{57}}{24}\)

Answer 2

\(\Delta=\left(-3\right)^2-4.12.\left(-1\right)\)

   \(=9+48=57\)

=> pt có 2 nghiệm:

\(\left\{{}\begin{matrix}x=\dfrac{3+\sqrt{57}}{24}\\x=\dfrac{3-\sqrt{57}}{24}\end{matrix}\right.\)