How to Solve general equation using Mathematica?

I am able to solve equation x^3 + 3x^2 + 3x + 1 = 0 using Mathematica by using the command

Solve[x^3 + 3x^2 + 3x + 1 == 0, x]

But not able to solve ax^3 + bx^2 + cx + d = 0 for general variables a,b,c,d using Mathematica.
Can anyone suggest me how this or any general polynomial equation of any degree could be solved using Mathematica.

Note that ax is not the same thing as a x or a*x.

In[7]:= Solve[a*x^3 + b*x^2 + c*x + d == 0, x]

Out[7]= {{x -> -(b/(
     3 a)) - (2^(
       1/3) (-b^2 + 3 a c))/(3 a (-2 b^3 + 9 a b c - 27 a^2 d + Sqrt[
         4 (-b^2 + 3 a c)^3 + (-2 b^3 + 9 a b c - 27 a^2 d)^2])^(
       1/3)) + (1/(
    3 2^(1/3)
      a))((-2 b^3 + 9 a b c - 27 a^2 d + Sqrt[
      4 (-b^2 + 3 a c)^3 + (-2 b^3 + 9 a b c - 27 a^2 d)^2])^(
    1/3))}, {x -> -(b/(
     3 a)) + ((1 + I Sqrt[3]) (-b^2 + 3 a c))/(3 2^(2/3)
        a (-2 b^3 + 9 a b c - 27 a^2 d + Sqrt[
         4 (-b^2 + 3 a c)^3 + (-2 b^3 + 9 a b c - 27 a^2 d)^2])^(
       1/3)) - (1/(
    6 2^(1/3)
      a))(1 - I Sqrt[3]) (-2 b^3 + 9 a b c - 27 a^2 d + Sqrt[
       4 (-b^2 + 3 a c)^3 + (-2 b^3 + 9 a b c - 27 a^2 d)^2])^(
     1/3)}, {x -> -(b/(
     3 a)) + ((1 - I Sqrt[3]) (-b^2 + 3 a c))/(3 2^(2/3)
        a (-2 b^3 + 9 a b c - 27 a^2 d + Sqrt[
         4 (-b^2 + 3 a c)^3 + (-2 b^3 + 9 a b c - 27 a^2 d)^2])^(
       1/3)) - (1/(
    6 2^(1/3)
      a))(1 + I Sqrt[3]) (-2 b^3 + 9 a b c - 27 a^2 d + Sqrt[
       4 (-b^2 + 3 a c)^3 + (-2 b^3 + 9 a b c - 27 a^2 d)^2])^(1/3)}}