Question

cho 2 đg thg d1: \(mx+6y-3=0\)

d2: \(x+\left(2m-1\right)y+m=0\)

gọi m1, m2 là 2 gtri m để d1 song song d2 khi m1.m2=?

Answer 1

d1 song song d2 khi:

\(\left\{{}\begin{matrix}m\ne0\\\frac{1}{m}=\frac{2m-1}{6}\ne\frac{m}{-3}\end{matrix}\right.\)

\(\frac{1}{m}=\frac{2m-1}{6}\Rightarrow2m^2-m-6=0\)

\(\Rightarrow\) Theo Viet \(m_1m_2=\frac{-6}{2}=-3\)