Question

Giúp em ý 2b) với ạ !

Answer 1

\(\Delta=\left(-m\right)^2-4\left(2m-4\right)\)

\(=m^2-8m+16\)

\(=\left(m-4\right)^2>0\) khi \(m\ne4\)

Answer 2

\(x_1=\dfrac{m+m-4}{2}=m-2\)

\(x_2=\dfrac{m-m-4}{2}=-2\)

\(TH_1:\left(m-2\right)^2=5.\left(-2\right)-1\)

\(\Leftrightarrow\left(m-2\right)^2=-11\left(vô.lí\right)\)

\(TH_2:\left(-2\right)^2=5\left(m-2\right)-1\)

\(\Leftrightarrow5m=15\)

\(\Leftrightarrow m=3\left(TM\right)\)

Vậy ...