一元二次方程（m-2)x^-4mx+2m-6=0只有一个实数根
(-4m)^2-4(m-2)(2m-6)=0
16m^2-8m^2+40m-48=0
8m^2+40m-48=0
m^2+5m-6=0
(m+6)(m-1)=0
m=-6 m=1