若﹙a+1﹚²+﹙2b-4﹚²+|c+三分之二|=0,
则:a+1=0,2b-4=0,c+三分之二=0
ab+bc+ac=-1*2+2*(-2/3)+-1*(-2/3)=-2-4/3+2/3=-8/3.