Given ax^3 + bx^2 + cx + d = 0
and roots are e, 2e, 3e
Find relation between coefficients.
I approached this firstly with addition of roots
6e = -b/a
e = -b/6a
Then subbed into equation to attain 5b^3 - 36acb + 216a^2d = 0
However, the solution proposes 11ad = bc, by solving via sum of roots, sum of roots 2 at a time and product of roots then combining together.
Which solution is correct or are they the same?