(x - a)*(x - b)*(x - c)*(x - z)
-(a - x)*(b - x)*(c - x)*(x - z)
4 3 3 3 3 2 2 2 2 2 2 x - a*x - b*x - c*x - z*x + a*b*x + a*c*x + a*z*x + b*c*x + b*z*x + c*z*x + a*b*c*z - a*b*c*x - a*b*x*z - a*c*x*z - b*c*x*z