Question

giúp em ạ, em cần gấp

Answer 1

2.\(x^2+2x+m-1=0\)

\(\Delta'=1+1-m=2-m\)

a)để 2 nghiệm nghịch đảo 

\(\Leftrightarrow\left\{{}\begin{matrix}2-m\ge0\\m-1=1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}m\ge0\\m=2\end{matrix}\right.\)

b)\(\left[{}\begin{matrix}x_1=-1+\sqrt{2-m}\\x_2=-1-\sqrt{2-m}\end{matrix}\right.\)

\(3x_1+2x_2=-3+3\sqrt{2-m}-2-2\sqrt{2-m}=1\)

\(\Leftrightarrow\sqrt{2-m}=6\\ \Leftrightarrow2-m=36\\ \Leftrightarrow m=-38\)