In[6]:= solution = Solve[a x^2 + b x + c == 0, x]
Out[6]= {{x -> (-b - Sqrt[b^2 - 4 a c])/(
2 a)}, {x -> (-b + Sqrt[b^2 - 4 a c])/(2 a)}}
In[7]:= {x1, x2} = x /. solution
Out[7]= {(-b - Sqrt[b^2 - 4 a c])/(2 a), (-b + Sqrt[b^2 - 4 a c])/(
2 a)}
In[8]:= x1 x2 // Simplify
Out[8]= c/a
In[9]:= x1 + x2 // Simplify
Out[9]= -(b/a)