∵/a+2/+2/b+1/+/a-c/=0
∴/a+2/=0,2/b+1/=0,/a-c/=0
a+2=0,b+1=0,a-c=0
∴a=-2,b=-1,c=a=-2.
∴a+b+c=-2+(-1)+(-2)=-5.