两边除以3m²+5m/3-4/3=0m²+5m/3=4/3m²+5m/3+25/36=4/3+25/36(m+5/6)²=73/36m+5/6=±√73/6m=(-5-√73)/6，m=(-5+√73)/6
3m^2+5m-4=0m=(-5+√73)/6 or (-5-√73)/6
