m²+4m-3m²-5m-6m²-2=-10m²-m-2当m=-2/3时,原式=-10×(-2/3)²-(-2/3)-2 =-40/9+2/3-2 =-52/9原题中“=”显然有误,故以“-”计算 有疑问,请追问；若满意,请采纳,谢谢!...