If every pair of equations `x^2+ax+bc=0, x^2+bx+ca=0` and `x^2+cx+ab=0` has a common root then their sum is

If every pair from among the equations x^(2)+ax+bc = 0, x^(2)+bx+ ca = 0, x^(2)+cx+ab = 0 has a common root, then the sum of the three common roots is

If every pair from among the equations x^(2)+ax+bc = 0, x^(2)+bx+ ca = 0, x^(2)+cx+ab = 0 has a common root, then the sum of the three common roots is

If every pair from among the equations x^2+px+qr=0,x^2+qx+rp=0 and x^2+rx+pq=0 has a common root, then the sum of the three common roots is

IF every pair from the equation x^2 +px +qr =0 , x^2 +qx + rp =0 and x^2 + rx +pq =0 has a common root , them the product of three common roots is

If the equations x^(2) - ax + b = 0 and x^(2) + bx - a = 0 have a common root, then

if each pair of the equation x^(2)+ax+b=0,x^(2)+bx+c=0 and x^(2)+cx+a=0 has common root,then product of all common root is